Video product design, Product management, Sales, Video Technology, Transmission products, Video security applications
Articles by Neil Heller
If one component within the infrastructure changes, other components may need to be changed too Developing a bill of materials for an infrastructure is not difficult if you have the right information. One word of caution: Infrastructures are unique. Each is individual, so don’t depend on drop-down menus; it simply will not work. If one component within the infrastructure changes, take the time to check and see if the rest of the components need to be changed, too. Let’s look at some questions and considerations when designing a network infrastructure for use by an IP/PoE (Internet protocol/power over Ethernet) video security system. First, you should work with individual collection points. This could be when all devices (cameras/access controller) are routed to a single location or when there are multiple locations as in the case of individual IDFs (intermediate distribution frames). For each location determine the following: Cameras And Number Of Cameras What are the manufacturer and model numbers for each camera? Knowing this will help to determine the bandwidth and PoE requirements. How many cameras are going to this location? If there are different cameras from different manufacturers, please list all of these by number. Break down these numbers further according to those that are 290 feet or less and those greater than 290 feet from a network connection and PoE source. You may think of IP/PoE limits in terms of 328 feet (100m) but conservative planning takes into account wire bends, which can contribute to increased resistance and decreased performance. Type Of Cable What cable is installed? Existing installations, those which will convert from analog to IP, probably already have either coax or fiber. For coax almost all existing installation will have RG59, but it’s important to confirm. Very old installation may even use aluminum shield cable, which will probably have to be replaced due to its high resistance. New installations will use Cat 5e or Cat 6. Fiber is more complex as you have to first determine the mode – single mode or multimode. Then you have to know the fiber size, which is usually a function of the mode. Single mode will generally be 9/1.25 while multimode can either be 62.5/1.15 or 50/1.25, depending on distance. Regardless, your fiber modems must match both of these aspects and bandwidth as well. The type of cable will also determine if you need extra equipment The type of cable will also determine if you need extra equipment as only UTP or Ethernet cable can be directly connected within a network. Coax, single pair and fiber will all require some form of media conversion. Cable Length Choose necessary extenders. As previously noted at each collection point, divide your device connections into those less than 290 feet and those greater than 290 feet. For the latter, use the longest cable distance as your reference and determine the type of extenders required to meet the bandwidth and PoE device requirements. Using any device in the transmission path will require you to take into account its effect on bandwidth and PoE. Network And PoE Source (This Can Be The Most Difficult Part) Managing the variables. While there are many IEEE standards governing network interconnections and PoE, the most important variables we are concerned with have no standards at all. They range from determining a real PoE budget, to how PoE is programmed, if at all, to internal switch bandwidth, sometimes called switch fabric, to the ability of individual ports to pass the required bandwidth from a camera. Two important things to keep in mind. First, your bandwidth must remain consistent throughout the transmission path. Second, your PoE source must be able to provide not only the power required to operate your device and any other devices in the path, but also power in the event of startup surges to avoid PoE shutdowns. Save
IP/PoE systems eliminate the need for local power, thus saving installation costs Cost considerations are an important reason to use existing installed cable as part of a new system infrastructure. Extenders in the form of media converters can help. For almost three decades, video surveillance systems existed in the form of analog systems. Video coaxial cable was the primary method of transmission with a limited distance of about 750 feet. Analog systems required separate power supply located at each security camera site. Today, new technology often solves one problem and creates another. Internet Protocol/Power over Ethernet (IP/PoE) systems eliminate the need for local power supply, thus saving installation costs. The drawback is the restriction to only 328 feet and the required use of Cat 5e or above cable. Extended Transmission Distance So tens of thousands of video surveillance cameras are waiting to be converted to IP, and have been transmitting over coax at distances two-and-a-quarter-times greater than the Ethernet limit. The advent of extenders helps to solve this problem. In addition, the use of extenders for Cat cable and even single-pair alarm wire helps to add to the types of IP/PoE conversions while extending distance as far as three thousand feet. Tens of thousands of camerasare waiting to be converted to IP,and have been transmitting overcoax at distances two-and-a-quarter-times greater than theEthernet limit Considerations While Using Extenders Use of extenders requires taking several considerations into account. First and most important is a careful reading of specifications. A statement can be true while not applying to your applications. Let’s take IP/PoE transmission over coax as an example. A manufacturer’s product can state it has this feature and will meet your transmission requirement of X number of thousand feet. However, a careful reading reveals that achieving this requires RG 6 cable while you have RG 59 installed. You need to maintain a 100Mbps bandwidth and provide your cable with 12.95 watts of power. But as both bandwidth and power decrease with distances obtainable from many types of extensions, you realize that both are much less at the extended distance you require. In short, just depending on a product to make a simple specification statement is not enough when it comes to infrastructure considerations and especially with regards to extenders. Save Save
When a manufacturer states a specific PoE power for a camera, always count on the maximum class power source Power over Ethernet (PoE) is an important consideration in IP video security infrastructures, and many people believe Institute of Electrical and Electronics Engineers (IEEE) standards are the last word. However, when it comes to PoE, there is a wide range of both voltages and wattages that can qualify as being within an individual IEEE power class. This applies to both the device being powered and the source of the PoE. A video surveillance camera may require the highest source voltage of 48 volts and highest source wattage of 15.4 watts to be considered as IEEE 802.3af, Class 3. However, a PoE source output of only 37 volts and 7 watts can also be considered as Class 3-compliant under the standard.Surge Factor In PoE-Powered DevicesThe surge factor is another consideration with regard to PoE-powered devices. In any consideration of power, it always takes more power to turn a device on than to maintain its operation. For video security cameras, this requirement applies both to startup and also to when we activate accessory functions such as day/night operation, LEDs, and auto back-focus to name just a few. If the surge applied when turning on these functions exceeds the ability of the source to provide it, or rises for more than approximately 40 milliseconds, the PoE source will stop transmitting power based on the safety built into the 802.3 PoE standards. It remains in that state until the port is reset either by turning power to the port off and on, or by disconnecting and reconnecting the Ethernet cable.A customer might interpret this type of problem to be a camera failure – it was working during the day and failed at night. He might return the camera to the manufacturer, only to be told there is nothing wrong. The solution is simple and two-fold: First, even when a manufacturer states a specific PoE power for a camera, always count on the maximum class power source. For example, if a manufacturer states a camera requires 10 watts and is 802.3af Class 3, you should always have a PoE source of 15.4 watts. Next, estimate any surge that might be present as requiring at least 20 percent more power. So in the case of the 10-watt security camera, that would really need about 12 watts, in this case putting it within the limits of a full Class 3 source of 15.4 watts. The problem will usually occur when the surge exceeds a particular class, especially at the transition from Class 3 to Class 4. The considerations regarding bandwidth and PoE are the same as with the camera or remote device Network PoE SwitchOnce we have determined the power requirements of the connected or remote site device, we need to turn our attention to the source that will provide PoE power and receive the signal. Often this is a network PoE switch. The considerations regarding bandwidth and PoE are the same as with the camera or remote device. The concerns here again are with the lack of standards and how specifications are determined. There are several factors to take into consideration.First, networking equipment in general is tested and specifications are determined using a packet size of 64 bytes. However, even the smallest one- to two-megapixel cameras will approach the limits of packet size testing at around 1,538 bytes, while cameras with two megapixels and above are even higher. In short, networking products are not tested using packet sizes comparable to those required by video cameras.Switch Specifications Once we have determined the power requirements of the connected or remote site device, we need to turn our attention to the source that will provide PoE power and receive the signal While many switch specifications will state they handle Jumbo frames, that ability is restricted to port programming at 1 Gbps speeds. In networking, the 100 Mbps output of a video camera must match the bandwidth input speed of the switch port.The second switch consideration is called the switch fabric, which connects all the switch ports. Its bandwidth must be at least two times greater than the sum of the highest bandwidth of all the ports. There is no standard for this, and the actual bandwidth is a reflection of switcher cost. With regard to PoE, be careful not to mistake the total power supply for the PoE budget for the power allocated for camera PoE power. They are different. If the total power were allocated to PoE, there would be no power left for switch functions. In addition, if all ports required PoE, the switch could easily overheat and fail. There should be anywhere from a 10 to 25 percent separation between the total switch power supply and the PoE budget. Finally, there are no standards for the methods used to allocate PoE power within a switch. It could be equally divided as more ports are connected. It could be programmed, or it could be fixed to each port. Save Save
The use of multiple wires has advantages for network transmission Network connection to a remote device begins by considering the type of cable. In some cases, installed cable may already be present and available for reuse, or you may have the option to install a new cable. Let’s review the major types of cable used for most security applications, their advantages and disadvantages. Types Of Cables In general, there are four major types of cable. First is coaxial cable, which, given the many decades of analog systems, has hundreds of thousands of existing connections. The second type includes Cat 5e and Cat 6, or what is commonly called Ethernet cable, the standard for network connections. The third is single pair cable, consisting of two wires and commonly used for alarm and access control applications. Finally, there is fiber, mostly used for long distances and outdoor applications. Coaxial cable, given the many decades of analog systems, has hundreds of thousands of existing connections Cat 5e and 6 are used for networking connections. The cable consists of eight wires, commonly referred to as four pairs. Under the IP transmission and PoE standards, two pair, four wires, are used. Each of the sets are referred to as “A” or “B”. The standard requires that IP/PoE devices operate over either. Within the “A” or “B,” one pair is used for data while the second pair for PoE transmission. Advantages Of Using Multiple Wires The use of multiple wires has advantages for network transmission. Running cables in parallel reduces resistance to power transmission. Cable twists are standard in Cat cable. Twisting reduces noise as the twist cancels out noise-causing resistance. The size of the wire is also standard at what is known as 24 AWG. The standardization of Cat cable serves as the basis of IP transmission in determining its limit at 328 feet (100 meters). This also applies to resulting power delivered to a device powered by PoE. Starting with a source of 15.4 watts (802.3af- Class 3), after 328 feet, the resulting power is 12.95 watts. For 30 watts (802.3at-Class 4), the resulting power is 25.5 watts. Other than Cat cable, no other type of cable can be used for IP/PoE without the use of a media convertor. The use of Cat cabling also allows transmitting PoE power higher than the current 802.3at source limit of 30 watts. Security camera manufacturers have developed video surveillance cameras with the ability to receive PoE on two wire pairs (rather than one pair) to what is in effect 802.3at. Given the highest voltage used for 30 watts which is 57 volts, up to 37 watts can be safely transmitted on a single pair and up to 74 watts using two pairs. This has given rise to the “60 watt PoE Cameras.” As two pairs are required, this application is restricted to Cat cables. Fiber transmission method is the most extensive, requiring extra equipment for transmission and reception Power Handling Capacity Keeping power in mind, one concludes that both coax and single pair will have much less power-handling capacity than Cat cable given that they are both single-pair transmission media. This means that both the signal and the power are carried over the same cable runs. There are several other important considerations for each. Keeping power in mind, oneconcludes that both coax andsingle pair will have much lesspower-handling capacity thanCat cable With regard to coax: While Cat cable is used to set a fixed resistance yielding the resulting power and fixed bandwidth over 328 feet, 100 metres, coax has no such standards as applied to IP/PoE transmission. In general, taken over 1,000 feet, Cat 5e resistance is about 22-27 ohms. For coax to have similar results as Cat 5e, it would need the same resistance values. However, that isn’t the case. Coax resistance varies even within the same category of cable, such as the standard RG59. Differences in resistance will affect performance. Noise Rejection Keep in mind that resistance Cat 5e cable also has standards with regard to the number and tightness of twists. These features affect noise cancellation within a cable. Single pair has no such standards and in fact can be found in flat wire configuration, which yields little or no noise rejection. Noise, in effect, is resistant to digital signals. Finally, there is fiber. This transmission method is the most extensive, requiring extra equipment for transmission and reception. Its qualities include long transmission distance. Due to its glass structure, it is protected against lightning strikes and high power surges. The problem is, fiber doesn’t transmit PoE. Its use will require local power sources and power supplies. Fiber also has to be matched to be a completely matched system. The modems used must match the fiber, and there are several considerations based on single or multimode, and the transmission frequency. Save Save
Too often we attribute failure of connected devices to the devices themselves when the problem is actually an infrastructure failure Network infrastructures for security devices are complex. It may seem simple to connect an Ethernet cable to a cable modem, but the connection of IP cameras, access control devices and other IP/Power Over Ethernet (PoE) devices is not nearly so simple. Infrastructure is the heart of any system; and too often we attribute failure of connected devices to the devices themselves when the problem is actually an infrastructure failure. Designing an infrastructure is made even more complex by the specifications we rely on. It is not that they are false; however, our belief that specifications represent fix values can result in applying equipment that falls short of accomplishing its goals. There is a paradox in designing infrastructures for IP video security applications: On one hand, networking is a matter of physics and leaves no room for variations. However, the physics apply only within certain conditions, and conditions can change. Here are the basic considerations in designing an IP video security infrastructure: Number of devices connected to network Number of devices routed to a single location Type of cabling used or already installed Cable length – usually the longest cable distance must be taken into account The PoE source: In most cases you will be dealing with devices powered by Power Over Ethernet Maintaining A Reliable Connection The goal is to have a reliable connection maintained over a variety of conditions. For this reason, it is important to start with the devices you are connecting. The most challenging of these are video cameras because we have to consider both bandwidth and required PoE power. Bandwidth is a function of the camera itself in terms of its megapixel size. But the rest is up to you – how many images per second, the codec and compression all determine bandwidth. There are simple rules concerning bandwidth. First, the higher the megapixel count, the higher the bandwidth. Second, the codec has a huge effect on bandwidth requirements. If we start with H.264 as a baseline, consider that MJPEG can require up to six times more bandwidth. A single stream of 4K can require up to 50 Mbps depending on the compression ratio applied. Understanding Video Compression Ratios The first step in considering how much network bandwidth is available is to realise the device bandwidth must be matched to all devices on the network Compression ratios are associated with the codecs they are compressing, and the combination of the two have their limits. In some cases, a camera can offer the ability to continually stream video at one compression and also provide individual alarm images of a higher resolution using a different codec. This requires taking into account the bandwidth required for both the continuous and alarm image settings. Fortunately, many of these settings can be controlled as part of the operator setup. This leads us to the most important bandwidth consideration, the network itself. The first step in considering just how much network bandwidth is available is to realize the device bandwidth must be matched to all devices on the network. For most security equipment that would be 100 Mbps. Quality Video Transmission Next is knowledge that within any bandwidth, only about half is available for actual data (video) transmission. The other half is taken up by overheads containing information regarding its transmission and reception points. In general, H.264 requires a safe allocation of about 2 Mbps; however, high-megapixel cameras and the use of other codecs could yield a requirement of up to 8 Mbps, thus reducing the number of cameras that can be transmitted over a single connection by a factor of four. A difference among infrastructure products, cameras and recording devices is that the latter enables judgment. You can visually judge if you accept a camera by the quality of its picture or how easy a recording device is to operate. The same is not true for the infrastructure, which is based on physics and is black or white. There is no middle ground and little forgiveness. When bandwidth isn’t enough, you can realize a condition called mosaic where the picture appears as individual blocks or out of focus, or with no picture at all. In any event, it’s not a judgment call. The 802.3 PoE standard has safety measures built-in to prevent transmitting power if no connection is made PoE Standard Safety Measures The same situation exists with PoE. The 802.3 PoE standard has safety measures built-in to prevent transmitting power if no connection is made or to shut down power in the event of a short. Once a connection is established and the power level required by the connected device is established, any raise in power for a period of time more than approximately 40 milliseconds will turn off power from the source. Any raise in power for a period of time more than approximately 40 milliseconds will turn off power from the source Let’s view this in more practical terms. A multiple PoE camera installation is completed during the day. During the night several accessory features on the cameras are activated such as Day/Night filtering and turning on LED. The PoE power increases sharply at first in order to activate the functions – this is known as surge power – prior to settling back to a lower operation level. The required surge power exceeds the power available from the PoE source, and all PoE power is shut off. The camera remains in the off position until reset. This often is a manual reset by powering down and up the PoE source or disconnecting and reconnecting the cable. In any event, the camera remains in off. Depending on the number of cameras and amount of PoE power, this usually doesn’t affect all the cameras, so a person commonly mistakes this for a defective camera. The same is true with bandwidth. Importance Of Networking Infrastructure Within a network you can think of both bandwidth and PoE as a bank with a set amount of funds. Each camera is a person withdrawing money. At some point you just run out of money, and the next person who makes a request either gets less than they requested or nothing at all. This helps to illustrate how important networking infrastructure is. It is made even more important by the differences between data and video networks. Data network requires bandwidth which, even for small megapixel cameras, is 96% less than video, while PoE for VoIP phones can be about 40%. Every component within a transmission affects all the components and as such the performance of the infrastructure as a whole. Save
Any wireless device can be a soft target for hackers Security network hacking is one of the hottest topics today. The ability to access security systems or devices anywhere, leaves them vulnerable and prone to hacking. Any wireless device can be a soft target for hackers. Let’s start with the concept that nothing on a network is really secure. Let’s admit this to ourselves and take the next steps to make our security networks more secure. Internet of Things Security We all want our networks to be the network of everything. We want to be able to access our security systems everywhere. We want to view cameras, receive alarms, get notifications on our cell phones or from access points that are not our own. We want to cut the cable with wireless transmission. All of these are just an invitation to make our systems less secure. We demand more security and blame camera manufacturers, video management systems (VMS) or network video recorders (NVR); at the same time, we want to pay less. We want the convenience of accessing everything over the Web and mostly using the Internet. Closed Network Security Systems No one is safe. In June, antivirus software provider Kaspersky Lab was hacked. Most of our security devices protect themselves with user names and passwords, and in most cases these are ineffective. The real protection is to limit access to a system as much as possible. In a typical network system, we have cameras connected to a network switch fed to a recording device usually in the form of a video server or NVR. The first question is: How much exposure do I really need? Video security used to be referred to as CCTV – closed circuit television. Sometimes, it still is. The key word is “closed.” Why not think about network video security systems as CNSS or “closed network security systems?” Every access point on a network has a potential for hacking. Once a security system is hacked, anything is possible. Studies have shown that hackers can exchange real video feeds from cameras for fake ones. It’s a variation on what used to be cutting the video cord or masking the lens in the analog days. So what can you do to prevent your system from being hacked? Create A Separate Network Let’s start with the obvious, make it a CNSS. This can be as political as it is technical, given that governance of security systems is shifting from the security department to IP directors who want to centralize their control. Next are the common sense approaches. If you can access IP devices by pinging them from any point outside your system, it is an open door for hackers. Every access point on a network has a potential for hacking. Once a security system is hacked, anything is possible Disable Common Access Port 80 which is most commonly used for Internet traffic should especially be disabled. Most network switches have the ability to be accessed with the help of a function called Telenet using ports 21 and 23 – disable these as well. Create Your Own Unique Subnet And IP Address An IP address is basically a 32-bit number that can range from 0 to 429496794, and has the potential to create about 4.3 billion unique addresses. Keep in mind, we are dealing with our own CNSS, so concerns about conflicts outside the network don’t exist. For example, if you are using an address of 192.168.1.xxx, with a subnet of 255.255.255.0, any IP address starting with 192.168.1 will be able to access devices on your network. Do You Really Need A Layer 3 switch? Keep in mind that “layering” as it pertains to network switches is primarily a marketing term and not a standard. The major difference in what we can consider a Layer 2-plus and Layer 3 is routing. A router routes IP packets among IP networks, which in our case makes it a major point of exposure. Think about routing in terms of Google. You ask a question, send it out and it crosses hundreds, perhaps thousands of access points on different networks until it is finally received at its destination, is responded to and is transmitted back to your computer over hundreds or thousands of additional access points. All of these cross different subnets over Wide Area Networks. Do you really need to have your system exposed to this for the privilege of paying more for Layer 3 capability as opposed to Layer 2? Most network switches have the ability to be accessed with the help of a function called Telenet using ports 21 and 23 – disable these as well User Names And Passwords They give us a sense of security, but in reality names and passwords are probably the least secure method. We now know that Android phones can be easily hacked without requiring the user to view a message or open an attachment. In doing so, all your information is exposed, including the phone application that allows you to view your security system. While a fix exists, due to the open source nature of Android it will be significantly more difficult to secure in comparison to single sources such as iOS. Network Switching - Most Critical Point The network switch is a gathering point for your security system. Once you have created your own network, removed access from outside networks by disabling common port access and avoided the use of routers or Layer 3 switches, you can take additional steps to internally secure your system. One of the most common and effective methods is the use of internal system MAC (Media Access Control) addressing. It is unique to each product that is IP-enabled. Your computer, cell phone and every component of your IP-based security system has a unique MAC address. Select a managed switch whose programming allows you to secure your system using MAC addressing. Your cameras can be connected to specific switch ports using MAC addressing, thus preventing them from unauthorized changes. Most importantly, the MAC address of the client computer can be tied to the switch to prevent outside or even internal access. This feature is known as MAC locking and is directly related to MAC lockouts, which disables unauthorized MAC addresses from gaining access. In the end, the decision as to how you construct your system network is up to you. Regardless of how attractive, the use of cell phones or the thought that Layer 3 must be better than Layer 2 switching are just invitations to hack your system. Every access point is another open door. Maybe it’s time to reconsider the meaning of “Closed Circuit.”
Just as with network switches, there are no real standards for midspans In general terms, a midspan is a power over Ethernet (PoE) power source that is placed between a network switch and the device being powered, hence the term midspan. The real question is, with almost all network switches providing PoE power, why do we need a midspan? The answer is, in some cases we don’t, but in others we do. As with any other product we have discussed, we need to first consider that, just as with network switches, there are no real standards for midspans. As with switches, you can wrongly determine the midspan you are considering has the required power by looking at the power supply without considering the actual power provided to each port and the total power available when each port is active. In short, a midspan can be the same as a network PoE switch without the switching capability. Midspans Expand Networks Involving High-Powered Security Devices The increasing power demands of many IP cameras such as day/night, LED on/off, auto back-focus and heaters/blowers have placed high demands on PoE power. Let’s start with the obvious: IP PTZ domes that require more than 802.3at (30 watts). Network switches don’t provide more than 30 watts of PoE port power. When called upon to do so, the normal reaction within the 802.3at operation is to shut down power to the port, thus rendering the camera useless. So when your camera requires more than 30 watts, you are going to need a midspan. Some camera manufacturers provide one with their camera; many don’t. If you are going to extend the range of power transmission beyond the normal 328 feet (and yes, you can), then you are going to have to account for additional power, and a midspan is a must. What Distinguishes A Smart Midspan From A Dumb Midspan? The abilities to be programmed, establish initial power, maintain power if lost, and communicate status are what separates a smart midspan from a dumb midspan However, thinking about a midspan in terms of power is too limiting. What else should a midspan be able to do? First, it should be managed. Power is expensive, and a midspan should be able to provide the ability to allocate power so that it can be applied to each camera in order to make the most out of the total available power. A midspan should be able to respond to additional power requests while still providing protection. We have previously noted that all cameras have power surges due to the startup of their accessory features. These are often the cause of port shutdowns. A midspan should have the ability to respond to these requests, while providing camera protection from over-power conditions; in short, the ability to tell the port to which the camera is connected to surge and provide the requested power for a specific and safe period. We know that network switches do not fuse their individual ports; therefore, a midspan, as it is a power device, should have fused ports so that if an individual port shorts, the rest of the ports and the mdispan will remain active. By the midspan’s position in front of the switch, the individually fused ports are actually providing port fuse protection for the switch itself. We know that in most cases once power to a port is terminated, a service call is likely if only to unplug the Ethernet camera to start the PoE cycle. The most important aspect of a midspan is to attempt to establish initial PoE, prevent its loss and in cases when PoE is lost, attempt to re-establish power. These abilities to be programmed, establish initial power, maintain power if lost, and communicate status are what separates a smart midspan from a dumb midspan. Many don’t consider the important, labor- and field service call-saving potential of a midspan; that is, a smart midspan that provides more than just power. Considerations for using midspan are often rejected on the basis of costs. However, consider that the most expensive components in a PoE switch are those that provide PoE power. Remove those and the cost of a switch is greatly reduced. The cost of a “smart midspan” may not be that much more than a network PoE switch with the same or even lesser power. Even less when you consider the cost of system downtime and service calls.
Layering as applied to computers is a made up term having no relationship to any particular standards When it comes to setting the criteria for network switching, we often hear “I only want a layer 3 switch.” We naturally assume that since the number 3 is bigger than the number 2, a layer 3 switch must be better than a layer 2 switch. It may surprise you, but when it comes to video security applications, this may not be the case. In fact, just the opposite may be true. Layer Is A Marketing Term And Not A Technical Term Defining a network switch is a difficult task, and adding the concept of layers just makes it more difficult. Layer is a term applied to the organization of protocols reflecting functions that must be performed in a certain order for programs contained within physical devices to communicate with each other. If all that is too complex, just realize layering as applied to computers is a made up term having no relationship to any particular standards. It is a Marketing Term and not a Technical Term. What Is A Layer 2 Process? In short, Layer 2 operates by learning the Media Access Control or MAC address of the device connected to each port and, when commanded, forwarding the requested information from that device to the requested port. For example: We have two security cameras, one connected to port one and the other connected to port two of the switch. At port three we have a VMS server. By knowing the MAC address of each of these devices, when the VMS server requests information from a camera, the switch knows that camera one is connected to port one and forwards that information to port three. The same process holds true for the camera connected to port two. Keep in mind every device, including your computers and cell phones, has its own unique individual MAC address. This process also applies to many of the internal workings of a network switch, primarily involving the setting up of VLANs and spanning tree operations, both requiring routing of devices between ports. Layer 2 Shortcomings There is one significant drawback to the Layer 2 process. All devices must on the same subnet and within the same address configuration. For example: 192.168.1.100 and 192.168.2.100 may seem to be similar IP addresses, but the difference between 1 and 2 places them on different addresses and prevents communication between the two. The same is true for the subnet. This is where a Layer 3 switch is used. It involves different types of hardware and software, basing the routing of signals on IP addressing which is common to all devices regardless of the protocol used. The simplest method to define the difference between a Layer 2 and Layer 3 switch is that Layer 3 contains routing that allows it to operate across different subnets. Difference Between Layer 2 And Layer 3 Process The simplest method to define the difference between a Layer 2 and Layer 3 switch is that Layer 3 contains routing that allows it to operate across different subnets. Your ability to access Google and other websites exists due to Layer 3 switching operations because all of these services exist on different subnets. To make matters even more complex, we often hear the term Layer 2+. What is Layer 2+? Look at it this way, if the number and features applied to define any layer are made up, the term Layer 2+ can be applied to any switch by any manufacturer for any reason. There are no standards. To us, 2+ is better than 2, so a Layer 2+ switch must be better than a plain old Layer 2. Too often we get tied up in the details and don’t look at how equipment performance applies to our actual application. Whether our security systems are analog or digital, CCTV stands for Closed Circuit. So you have to question why any security system would want to pay extra for a feature that will not only will not be used, but probably shouldn’t be used. Yes, Layer 3 switches cost more than Layer 2, and expose themselves to more potential outside access. Why would a video security system want to run on different subnets? Usually most security systems are not major networks, and the primary concern is the amounts of usable bandwidth allowing all the cameras to be fed to a single recording point. What role does Layer 3 play in this? You can configure switches within the same network using Layer 2 to communicate with each other. You can establish a single switch to serve as a network backbone, communicating with other switches to create a single communication point. Using a process known as Stacking, you can designate one switch as a “Master” and use it to receive access to other switches in the network. These can all be accomplished with Layer 2 switches. All within the same subnet. What is the advantage of operating a single security system as different networks? If numbers are that important, consider this, there is a Layer 7!
Too often a valid assumption turns out to be the opposite in practical operation It’s easy to misinterpret product specifications of IP video transmission products to the detriment of system functionality. We have seen how this problem relates to port speed, power over Ethernet (PoE) and transmission media. Now let’s look at some additional aspects of product specifications – and how they can be misinterpreted. Importance Of Temperature Rating What about temperature? Most transmission product specifications will have an extended temperature rating, and it is a consideration for products installed in extreme environmental conditions. But how was that specification obtained? Is it based on actual product testing or is it taken by the rating of the individual components? The latter proves nothing. This is particularly important if the product in question requires a local power supply. Most extended distance products are compact. If local power sources are required, it will speed up internal component deterioration and shorten operating life. Effect of Latency Or Cable Delay Then there is the question of latency or cable delay. This factor can have an important effect on how you view your security camera. It is especially critical if your system includes PTZ, as the action of moving the joystick should closely follow the camera movement response. This is where how a cable extender achieves its function is important. Some manufacturers reconfigure transmitted packets at the control site and reestablish them at the camera site, similar to the process of encoding and decoding video. This is often noted when an extended system has a separate transmitter and receiver. This process not only requires a great deal of power but also injects a signal delay to the point, resulting in PTZ positioning problems. Call the manufacturer to address areas that are unclear. Even ask the manufacturer to provide test results and descriptions of test methods. It’s less costly and time consuming than the alternative. Role of Bandwidth And PoE Transmission Over System Cost Then there is the subject of multiple channel extended bandwidth and PoE transmission. From an installation standpoint, this can lead to substantial cost savings. However, once again looking beyond the stated specification is key. In most cases, we are dealing with four channels. The logic is simple and effective, providing the ability to transmit four IP cameras on single Ethernet (UTP) or coax cable. The specification states bandwidth is 100Mbps. Is the specification applied to each of the four channels or the system as a whole? If the latter, then each channel has a maximum bandwidth of only 25Mbps. Keep in mind that is IP packet transmission takes up to 50 percent or greater of this bandwidth with packet overheads reducing the usable per channel bandwidth to 12.5 Mbps, a level that can be important when attempting to transmit high-pixel-count cameras and high frame rates. The same applies to PoE. If a single power source is used, it also is divided by four. Distinguishing Switches And Hubs One of the most important specifications that is usually unaccounted for relates to switching. Anytime you consider transmitting more than one camera on a single path, you have the potential of camera transmissions conflicting with each other. If a product transmitting multiple cameras on a single path doesn’t include references to switching specifications, you can assume you are dealing with a hub. The differences between a hub and a switch can be illustrated by looking at a four-way intersection. The hub is an intersection with no traffic lights or stop signs; each cars proceeds across the intersection once they reach it. A switch has regulation in the form of either stop signs or traffic lights. In the case of a hub, a car (or in this case a transmission from a camera) will not make it across. Look for a claim of layering, which will clearly identify the product as a switch. Review Product Specifications When it comes to transmission specifications, what does compliance to specifications really mean? Does it mean operating under several different conditions that must all be true at the same time? Does it mean that only part of the system, such as the Ethernet port itself, is capable of handling a particular bandwidth or PoE power level? Dealing with transmission products, the answers are left to the reader – and too often a valid assumption turns out to be the opposite in practical operation. The result becomes system removal, numerous service calls, back and forth blaming various manufacturer component within the same system, and, worse, the loss of functionality on the part of the user and credibility on the part of the dealer. Better to take the time to review product specifications. Call the manufacturer to address areas that are unclear. Even ask the manufacturer to provide test results and descriptions of test methods. It’s less costly and time consuming than the alternative.
4K places extra demands on video security but the results can be rewarding Since last year there has been a lot of talk with regard IP security cameras with 4K resolution. As with any advancement in video security, this too has come about due to advances in consumer electronics. While being the “latest and greatest,” it still raises questions as to actual, practical everyday usage. What Is 4K Resolution? Let’s start by defining 4K. Back in the day we had HDTV, which in some cases was defined in terms of its resolution of 1920 horizontal pixels by 1080 vertical pixels, hence the name 1080p, the p standing for the type of scanning – progressive scanning. Our concern is with the result of multiplying these numbers, or 2 million, which for us means the need for at least a 2 Mbps bandwidth to transmit an image. 4K is four times that number or a resulting 8 Mbps required to transmit an image. None of this would cause any concern if it were not for the fact that our observations deal with motion, and motion deals with multiple images over the period of a second. The question then becomes how to view it and how to record it. If we do not consider how we will transmit it between the image source and either its recording or viewing point, nothing will happen. All of this places significant stress on our existing IP infrastructures. While many believe the solution is simply to upgrade networks to 10 Gbps, they overlook the cost, viewing and recording aspects. The reality is camera manufacturers have taken this into account. In some cases cameras offer the ability to view signals by reducing the signal down to 1080p while maintaining the 4K for recording. Challenges To 4K For Security To understand the challenges to 4K for security, we need to take a closer look at the signal itself. As previously noted 1080p is 1920x1080 pixels. 4K is four times this or 3840x2140. While standards don’t necessarily apply in video security applications, 4K does have a standard as defined by the International Telecommunications Union (ITU). Taking into account the need of security applications to be “real time” or close to 30 images per second, the total bandwidth required for a 1080p single at 30 images per second would be 93 Mbps, and for 4K it rises to 373 Mbps. Both of these figures would be impossible to deal with given current viewing or recording technology. However, when we apply current standard compression method of H.264 which is generally 50:1, 1080p bandwidth is reduced to about 2Mbps and 4K to 8Mbps. Prior to designing a system involving 4K devices, make certain you work with a transmission provider that can justify their performance and provide support in the event you require it Role Of Transmission And Bandwidth A word of caution here. Keep in mind: While there are standards, they don’t apply to how any individual camera or video management system (VMS) provider applies it to their products. This is the reason different IP camera manufacturers have different and often incompatible drivers for resolving their cameras. Here is where transmission and bandwidth play a critical role. Keep in mind that on the average packet overheads will take up around 50 percent of a transmission system’s available bandwidth. So a transmission speed of 10 Mbps only has about 5 Mbps available for image transmission, a 100 Mbps only about 50 Mbps. If the basic highest compression H.264 bandwidth already requires at least 8Mbps, we can immediately eliminate the use of any part of the system that only operates at 10 Mbps. Even at 100 Mbps, the number of 4K cameras in any transmission line can probably only safely be limited to around four. Differences will result based on the other factors such as the number of images per second produced by the camera. The critical factor is to take into consideration every aspect of your transmission system. To begin with, when it comes to connecting the 100 Mbps output port of the camera to your network switch, the port must be able to resolve Jumbo frames up to 9600 bytes. Keep in mind the output network speed of the camera must match the input port speed of the switch. Most network switches can only resolve up to 1518 bytes at 100 Mbps, figures not adequate for 4K camera transmission. Next, your transmission line, regardless of the type of medium used, must have a consistent bandwidth from one end to the other. As your device bandwidth increases, network transmission losses become more critical. While viewing and recording device performance can usually be judged by their manufacturer-provided specifications, transmission often is more difficult due to the various components involved. Prior to designing a system involving 4K devices, make certain you work with a transmission provider that can justify their performance and provide support in the event you require it. 4K places extra demands on video security but the results can be rewarding.
Misreading specifications of transmission products can lead to making the wrong selection Manufacturers’ product specifications are the main source of determining product purchases for video security users. In many cases, the ability to pretest a product under the actual operating conditions is almost impossible. Often the choice is between several different product manufacturers. The time and expense it would take to install and evaluate each one in the actual application would be cost-prohibitive. Some product categories have advantages. A camera’s low light capability, for example, can be somewhat evaluated by decreasing the input light in any location. A video management system (VMS) can be evaluated by operating it under similar conditions. In both cases, the selection process can be based on a matter of opinion. For the camera, the opinion is the user’s view of quality. For the VMS, how comfortable are the operations? Transmission Products’ Specifications None of this applies to transmission products. The ability of moving signals is a matter of physics that is usually black and white. No manufacturer tries to use specifications that are untrue; however, your misreading can lead to making the wrong selection. With transmission products, it is a good idea to go beyond the product specifications and also review the product’s operating manual. What specifications are not included? Taking these additional steps can reveal factors that have substantial effects on your system performing as expected. How To Choose A Network Switch? Let’s start with a network switch. Its specification might indicate a port speed of 1Gbps and the ability to handle jumbo frames with packet sizes up to 9600 bytes. True; however, what you have overlooked is the connection from the network camera requires a port speed of 100Mbps, and misalignment of port speeds can lead to dropping of frames. At a 100Mbps port speed, packet sizes are limited to 1518 bytes. Potential video quality problems can exist with cameras greater than 3 megapixels. For determining if the switch will meet your application requirements, you need to focus on the PoE budget. If the manufacturer doesn’t provide it, the safest approach would be use 75 percent of the specified power and divide it by the number of ports. The switch specification states a port power of 30 watts is compliant to 802.3at. True, but is doesn’t state that all ports can provide 30 watts at the same time. The likelihood is they cannot. The statement is true; however, it still may not meet your application requirement. The switch specifications provide a figure for operating power. You divide it by the number of ports or the number of ports you need to provide PoE and determine there is enough power for your application. True, well maybe, as you haven’t taken into account the power required to operate the switch. Not all switch manufacturers provide both a total power specification and a separate PoE budget. For determining if the switch will meet your application requirements, you need to focus on the PoE budget. If the manufacturer doesn’t provide it, the safest approach would be use 75 percent of the specified power and divide it by the number of ports. You have applied an operational power overhead to the switch, but in actual operation it might still not provide the port PoE power you need. The reason might be the switch’s operation with regard to how PoE is applied, which is not included in the product specifications. The switch may only provide the ability to turn all the ports on and off; dividing PoE equally between all the ports or PoE is applied only based on port priority. Complications While Selecting Transmission Medium From the switch we move to the transmission medium. Here it is important to note that all specifications are based on the IEEE transmission standards using UTP cable. For our applications, that would be Cat 5 and above. If your application has to travel over Cat 3, and the product specifications doesn’t show a Cat 3 specification, it is a good idea to check with the manufacturer. For any application that transmits over distances greater than 328 feet or on a medium other than Cat 5, you are dealing outside the normal specifications, and performance is only decided by the equipment manufacturer. This is where things start to get complicated. As long as the power at the end of the longest distance meets the lowest figure, the specification itself is true even if it fails to properly power your camera. The manufacturer claims their product transmits at 100Mbps. True, but do they mean 100Mbps in both directions or do they mean 50 Mbps in both directions? The statement would be true in either case. The manufacturer claims an operating distance of 5,000 feet. True, but in the case of bandwidth, what hasn’t the manufacturer told you? They have omitted the bandwidth available at the highest stated distance. Even if that bandwidth is only 1Mbps, a level that would not be acceptable for most IP cameras, the statement is still true. Nowhere is there any indication within the specification of the ability to handle jumbo frames. Keep in mind that most networking products are tested and claims made based on the ability to handle 64byte, a figure that doesn’t come close to the lowest video packet size of approximately 1024 bytes. These can be embedded in any number of specification claims. What packet size is the manufacturer basing its claim on? Bandwidth and packet size take on more importance when it comes to large systems that use multicasting. This feature of cameras and video management systems helps to reduce bandwidth when dealing with large groups of cameras. The key is the system bandwidth must be large, at least at 100Mbps and must be maintained throughout transmission distance. Decreases in bandwidth will render multicasting inoperative. PoE Selection: The same approach applies to PoE. The specifications state it provides 802.3af power, but at what class? Keep in mind PoE power is defined in classes, each of which has a range of power. That statement can be true even if the power at the longest distance is under 4 watts. If the specification states the extender is capable of 802.3at power, that statement is true if the power level exceeds 15.4 watts. It doesn’t have to be at any power level above that. As long as the power at the end of the longest distance meets the lowest figure, the specification itself is true even if it fails to properly power your camera. What level of power within a PoE class claimed within a product specification is actually produced? Determining Cable Performance Finally there is the question of the cable itself. If the extended medium is UTP, are the associated specifications based on the more commonly used Cat 5e, or based on the more expensive Cat 6 that has better performance characteristics? Also, don’t make the mistake of assuming the performance specification stated for Unshielded Twist, is the same for Shield Twist. The latter has very different characteristics that affect the transmission of both bandwidth and power. When it comes to single pair, twisted or untwisted, or coax, there simply are no standards for IP and PoE transmission. Here, also, it is important to understand the association between the stated specification and the cable you require. In most cases conversions of existing analog video security system to IP will involve standard RG59 cabling. Within the family of RG59 cabling, there are several different types of cable resistance. Fortunately, most of the common cable used will have a cable resistance that closely matches that of Cat UTP used for determining 802.3 performance. However, there are exceptions. Most often you may find a manufacturer stating coax maximum distance performance based on either RG11 or RG6 coax cable. As the main reason for using Coax to Ethernet extenders is to avoid pulling cable and the associated costs, it makes no sense to have your requirement met if you do have replace the cable in order to achieve your distance goals. Role Of Power Source In Deciding Performance The question of power also brings up the question of the power source. In an ideal installation you should be able to use the existing power from a PoE network switch. What power source is the performance specification based on? In some cases the ability of a cable extender to achieve its stated maximum distance is based solely on the use of its own power supply, usually at extra cost. Or it can be based on the requirement that the extender at the camera location have a power supply adding cost not only for the power supply but also for the need of an outlet. However, in both cases statements relating to distance and the ability to provide a particular, usually high, power level are true. Nowhere is the subject of PoE over coax more confusing than when it is applied to the need for 60 watts. Physics dictate the higher the power level the shorter the distance. Additionally, coax has more a resistance to power than UTP (Ethernet). In most cases, the actual ability to transmit 60 watts over coax provides a very short distance with the rest of the product carrying either multiple ports of 30 watts or a combined port of a value over 30 watts on Ethernet cable. However the claim of “We can transmit 60 watts over coax” remains true, it just overlooks the subject of distance or the practicality of your actual applications.
Differences between standard data applications and the requirements of networks designed for IP video security applications are critical for your system's performance When the need to purchase a network switch arises, many IT directors immediately turn to two favorites, HP or Cisco. They have become to the networking environment what IBM was to computers: “No one ever got fired for buying IBM.” Certainly, switches play a crucial role in enhancing your network by increasing its speed and capacity. However, it is equally important to note that they can also slow down your network and the same is explained in the article by Neil Heller - Vice President, Vigitron, Inc. With the transition of video security systems from analog to digital, IT network directors overlooked a key point in their rush to expand their jurisdiction over networking by adding the video security element. The fact is, IP video security networking requirements are not the same as those used for data networks. True, video transmitted over a network is data, but that is where the similarities end. Network switch and its worthiness to IP camera Nowhere are the differences more apparent than related to network switches and midspans. Let’s start by examining a standard network switch and its non-functional relationship to IP video security cameras. We will begin at the switch port. In networking, information is transmitted in the form of packets. For most network switches, when the port is set at 100Mbps, the packet size is limited to about 1518 bytes. This is equal to about a two to three megapixel camera depending on the codec used, H.264 generating the smallest packet size and MJPEG the largest. Some switches that have port speeds to 1Gbyte can be programmed up to the Jumbo Frame, which defines packet sizes greater than 1581 bytes. Jumbo Frames are those that range between 1518 bytes and 9600 bytes. This latter ability wouldn’t present a problem with the exception that in networking, the output speed of a device must be matched to the input speed of the port. As all IP cameras have output bandwidth speeds of 100Mbps, the input speed of the port must be set to 100Mbps. If the switch has an automatic port speed setting, it will sense the input speed from the camera and no manual setting is required. The problem exists when the packet output from the camera exceeds the limitation of the switch port setting at 100Mbps. In short, you can have issues with any cameras that are 3MP or greater. If an NVR or VMS server is not communicating with an individual camera, you don’t know if the problem exists at control site device or the camera. Little consideration is given to the idea the problem may be the switch port and camera Switch fabric estimation The second concern is the internal switch connection between all the ports. This is called the switch fabric or throughput. In most normal data applications, either not all ports are used or the data at each port is far less than the port’s highest capacity. Again, this is not the case with IP video security applications where all ports are used and each port needs to operate at its highest bandwidth capacity. For this requirement, the switch fabric must be able to handle at least two times the total bandwidth of all the ports. For example, if you have a 24 port, each port with the ability to operate at 1Gbytes, the switch fabric must have a bandwidth of at least 48Gbyte. Please note, there are no standards for switch fabric or port bandwidth packet size capacity. These are both quality issues. The potential problems become clear as the megapixel size of a camera increases, as does the camera’s codec, and as the number of cameras in your system approach the maximum number of switch ports connected. The problem is often misunderstood. Operators don’t know why they only have good video quality when the camera capacity is less than the switch input maximum. PoE-related concerns Just as critical is the interaction between switch functions, or lack thereof, concerning PoE. Many of these center around the lack of protection. This starts with the individual port, which is not fused. Shorts in any individual channel can render the entire switch inoperable when the main power fuse is broken. During normal startup, PoE power required by each connected camera is sensed. If a short exists, or no camera is detected, or the amount of power requested by the camera exceeds the available port, the port will shut down. This is a function of the normal safety built into the 802.3 standards designed for PoE. When this occurs, the port is basically off and remains in the off condition as the physical Ethernet connection between the camera and switch port has already been established and new detection pulses are not generated. There are several reasons this can occur. Even in properly installed systems, a good port-to-camera connection is not always established on the first try. Again, blame usually is placed on the camera. In some case, removing the Ethernet cable and reinserting will reestablish the connection. However, the first reactions are most likely to request a return authorization from the manufacturer or ask for a service call from the dealer. The second PoE-related problem is best illustrated by an actual installation. Several schools in a distant had PTZ cameras with more than half their inputs into a single PoE switch. As PoE power was applied, the PTZ domes move to their reference position, resulting in a surge so great that it damaged the switch’s power supply. While the safety built into the 802.3 standard can protect the individual port, it does not account for potential high power surges at the actual startup. For PTZs and other accessory features, the surge occurs only after initial communication is established and PoE power applied. The standard only applies to sensing the need for PoE, and if the PoE power requested is available. There is no protection against surges or the number of ports within a switch that are subject to surges. During normal operation, a PoE network switch has no ability to account for surges occurring from PTZ, LED, Day/Night, Auto Backfocus, and other accessory features During normal operation, a PoE network switch has no ability to account for surges occurring from PTZ, LED, Day/Night, Auto Backfocus, and other accessory features. If these occurrences have durations of greater than approximately 40ms or require more power than available at the port, port PoE will simply shut down, rendering the camera useless. This is a concern when the normal operating power of the power of the camera is at the edge of an individual power class and the surge exceeds that class power limit. Within a network, connected devices pass through the switch. There is no connection accountability between the switch port and device connected to it. As such if an NVR or VMS server is not communicating with an individual camera, you don’t know if the problem exists at control site device or the camera. Little consideration is given to the idea the problem may be the switch port and camera. Finally, there is the AUPC, or Actual Usable Port Count. A 24-port switch does actually have 24 ports, but when you consider that a least one port is connected to the recording or viewing device, the usable port count is reduced to 23, if the switch is connected in a series then you use two ports and the count is further reduced to 22. All of these define the differences between standard data applications and the requirements of networks designed for IP video security applications. These differences are not defined by nor part of any of the standards that govern compatibility in networking standards. They are, however, critical in the performance and reliability of your security system.
Standards for camera manufacturers presented a new challenge with the introduction of security cameras that require more than 30 Watts of power Standards for camera manufacturers presented a new challenge with the introduction of security cameras that require more than 30 Watts of power. Many of these involve pan-tilt-zoom (PTZ) domes and heaters and blowers that require additional power. This development created two areas of confusion which is highlighted in this article by Neil Heller - Vice President, Vigitron. The first is the ability to define what a 60-watt camera is and what power sources are actually required. The second and more serious is how to provide that power. Both share a commonality in that they lack any form of standardization. PoE To Power 60-Watt Security Camera Alone? Let’s start with the definition of the 60-watt camera. As the term suggests, it requires 60 watts or greater, but that doesn’t necessarily mean all the required power comes from a single PoE source. In many cases, camera manufacturers require that PoE only power the camera itself. Looking at these cameras’ power specifications will indicate a required PoE power of 802.3at or 30 watts, thus leaving power to the heaters and blowers requiring a local AC power source. This situation brings into question the value of PoE power if it is restricted to only providing camera power. Another group of PTZ cameras does use PoE for both camera and heater/blower functions, but only when the heater operates within a restricted temperature range. This usually means if your camera is installed in areas where the temperature that can fall below -20 degrees C (approximately -20 degrees F) you will still need a local power AC power source. The third type of security camera relies only on PoE power for both PTZ and heater blower operations. This is confusing, and is often the source of users finding their PTZ has failed at the most inopportune time. Any attempt to transmit 60 watt power over coax cable that is only a single pair should be considered with a great deal of caution, requesting from the transmission equipment provider that they will accept liability for any damages PoE For Greater Than 30 Watt Applications The three different operations of how these “PoE” cameras are powered brings into question the value of using PoE for greater than 802.3at, 30 Watt applications. Value exists in the ability to centrally control power operations from a single accessible point. Certainly those cameras that are solely dependent upon PoE have the greatest advantage. This brings to the second point of confusion, the composition of the PoE power. To review a brief history, 802.3af (15.4) was the first PoE standard used for IP cameras and is for the most part a standard. 802.3at (30 Watts) was introduced as four different standards, two of which, Type 1 and Type 2 are supposed be compatible, but in reality are not. Transmission Restriction Over Physical Cables 60 watts has no standards. To understand this, we need to look at the limitations of transmitting power over physical cables. Any form of transmission over a physical media has limitations in the form of resistance. As resistance increases, so does the heat generated by this process. The higher the power, the greater the resistance and resulting heat generated. Based on CAT5e cable, a single wire can handle about 0.75 amps. In PoE transmission, power is transmitted on a pair of wires or 0.75amp X 2= 1.5amps. According to the 802.3at specifications, Class 4 specifications generally are considered to start around 48 volts. So we take 48 x 0.75= 36 watts or 72 watts for the pair. Dual PD (Power Device) System So how do we get to 60 watts? For “over” 30 watts, camera manufacturers use a dual PD (power device) system. In short, it operates as if it where two IP cameras and requires use of all four pairs within Cat cabling. Exceeding these power limits can be dangerous in overheating the cable and its installation. Therefore, any attempt to transmit 60 watt power over coax cable that is only a single pair should be considered with a great deal of caution, requesting from the transmission equipment provider that they will accept liability for any damages. The need to operate two PDs within a single camera is where the incompatibility exists. There are no standards as to the sequence of turning on separate PDs in a single camera The need to operate two PDs within a single camera is where the incompatibility exists. There are no standards as to the sequence of turning on separate PDs in a single camera. Most such camera manufacturers provide their own PoE source in the form of a PSE or camera power supply; however, don’t try to interchange these power sources among different cameras from different manufacturers as they will not work. If you attempt to use a third party version, make certain you confirm that the power source manufacturer has actually conducted certification testing and can provide proof of compatibility or provide any operational limitations. Distance Of Transmission Finally, there is the question of transmission distance. This takes us back to the physics of high-powered PoE transmission. Even with manufacturer-supplied PSEs, the distance limitation is still 328 feet (100m), the Ethernet standard. Most applications such as perimeter and parking lots will be hard pressed to find a power outlet within 328 feet of where the cameras needs to be installed. This is where third-party transmission equipment providers come into play, but again the ability of transmitting 60 watts PoE power for distances greater than 328 is more complex that standard 802.3af and 802.3at, and more limited. This combined with the non-standard make a detailed knowledge and interaction with the manufacturer critical to a successful installation.
PoE power is a complex issue in itself made even more complex by the lack of standardisation Standards are like a warm blanket on a cold winter night. They make us feel safe and warm. A standard tells us the devices we use within our systems will interact with each other regardless of manufacturer. For IP-powered PoE devices, we depend on standards such as 802.3af for devices requiring up to 15.4 watts and 802.3at for devices powered up to 30 watts. We depend on the devices generating the power to be able to be read by devices receiving the power. Our dependence is not always justified. Let’s see the reasons why. The first has to do with 802.3af Classification, which covers within a range of source and receiving device power ranges. THE IEEE 802.3AF VS. IEEE 802.3AT AT A GLANCE The following table shows a comparison of the 802.3af and 802.3at standards, highlighting the key system-level differences. The following definitions are transcribed directly from the IEEE802.3at Standards Draft: Type 1 PD: A PD that advertises a power draw less than or equal to 12.95W (at the PD). Type 1 PSE: A PSE that is designed to support a Type 1 PD. Type 2 PD: A PD that advertises a power draw greater than 12.95W (at the PD). Type 2 PSE: A PSE that is designed to support either a Type 1 or a Type 2 PD. PoE vs. PoE+ Differences FeaturesPoE (802.3af)PoE Plus (802.3at) Cable Requirement Category 3 or better Type 1: Category 3 or better Type 2: Category 5 or better, with DC loop resistance < 25 Cable Current (A) 0.35 A Type 1: 0.35 A PSE & PD Type 2: 0.6 A PSE Output Voltage (Vdc) 47 – 57 Vdc Type 1: 47 - 57 Vdc Type 2: 50 - 57 Vdc PD Output Voltage (Vdc) 37 – 57 Vdc Type 1: 37 – 57 Vdc Type 2: 42.5 – 57 Vdc Maximum PD Wattage (W) Class 0, 3 12.95 W Class 1: 3.84 W Class 2: 6.49 W Class 4: Unused Type 1: Class 0, 3: 12.95 W Class 1: 3.84 W Class 2: 6.49 W Type 2: Class 4: 25.5 W Classification Requirements 1-Event Classification is optional for PSEs and Mandatory for PDs Type 1: 1-Event Classification is optional for PSEs and Mandatory for PDs Type 2: PSEs can deliver 2-Event Classification only, LLDP only, or 2-Event Classification and LLDP. PDs must respond to 2-Event Classification AND LLDP Any power level within this range can be classified with its associated class. So a source that provides any power level received at the device between 6.49 watts and 12.95 watts can be called Class 3. Even more confusing: Any received power level over 12.95 watts can be considered to be Class 4. The detection pulse variations that trigger the IP PoE device to turn on follow the same confusing range. So, regardless of whether we are determining the value of detection pulse voltage or applied power, the use of Class does not provide us with any fixed valued. While waiting around for standards committees to come with a high-powered solution, the PoE chip manufacturers decided to go on their own. This provides two different approaches to 802.3at or 30 watt solutions. This situation is the cause of confusion. Many times an IP camera specification will read both a specific power value and Class, with the former being less than the upper limit of the class itself. In this case, always plan on designing your infrastructure requirements for the highest PoE value. This takes into account the extra power required by the camera to handle surges. The listing of the Class power also gives the manufacturer the ability to claim that any camera malfunctions are a result of not providing the power required on the camera specification sheet. The lack of “standards” doesn’t end with power. While waiting around for standards committees to come with a high-powered solution, the PoE chip manufacturers decided to go on their own. This provides two different approaches to 802.3at or 30 watt solutions. Within the PoE process, the PSE or power source first detects the presence of the device requiring PoE, next it issues the detection pulse in the form of a voltage; this is known as a one event classification. However, if the receiving device requires more than 12.95 watts (15.4 at the PSE), a second pulse is issued within 10ms of the first. Or not! The “standard” can accept either a one- or two-event Class classification. So much for standards. In reality, the one-event, known as Type One, and the two-event, known as Type Two, are supposed to be compatible. The reality is very different, and often problems result from a Type One PoE power source being used with an IP camera. The results can be anything from a camera not powering up to an on-screen display stating their isn’t enough power when in the reality the camera is functioning normally. But wait there is more! Regardless of whether 802.3af or 802.3at power is used, the structure of detection pulses can differ. Detection pulses can be either 4 point or 2 point. As with classification, a camera responding to either might ignore one or the other. A non-response to a detection pulse means the source providing the power will interpret there is no devices and shut down power. Sources providing power under the PoE standard are not required to generate both versions and there are known differences in how cameras will respond. In short, PoE power is a complex issue in itself made even more complex by the lack of standardization in what is supposed to be a standard.
The action of a voltage applied to a resistance element, draws power from the switch’s PoE port We often think about a power supply operating in a single format. A power source provides power to a device. You plug it into a wall outlet and that’s all that happens. PoE power is a far more complex. There is interaction between the source providing power and the device receiving power. This interaction is governed under the 802.3 AF and AT standards. These differences can have a dramatic effect on the safety and security of a system. Let’s look at a simple system. We have a PoE source in the form of a network switch, an Ethernet cable and a PoE camera. The switch is powered; the camera is not. When the Ethernet cable is used to make the connection between the switch PoE port and camera, the switch issues what is known as a Detection Pulse in the form a voltage. This detection pulse is received by the camera, which looks like a form of resistance. The action of a voltage applied to a resistance element, draws power from the switch’s PoE port, beginning the power flow to the camera. The first thing to notice is that power from the switch to the camera does not begin to flow until the power required by the cameras is requested. The detection pulse is key to the process and can be thought of in terms of a switch. The second point is that, by the camera requesting power, it is also establishing the level of power required. In short, the camera and switch’s PoE port are communicating with each other. Keep in mind that cable resistance also plays a role in the process. The 802.3 standards established for PoE protects the device providing the power, which is referred to in the standard as the Power Source Equipment or PSE; and the device being powered, which is called the Power Device. These functions of communication, standardization and safety help distinguish the differences between a PSE and an injector, which is often misused. An injector has none of these communication or safety functions, it is merely a power outlet. The only way to stop power flowing in the case of a short or power levels exceeding that which can be safely handled by the camera is for either the power supply or camera to burn up. Lower prices for injectors as compared to PSE may be attractive until you realize the actual potential costs. "The 802.3 standards established for PoE protects the device providing the power, which is referred to in the standard as the Power Source Equipment or PSE.." The process appears to be simple until you break it down into its components. PoE is actually a three-step process: Step One is “detection pulse.” When a PoE camera is plugged into a PoE source, it is off. The action of plugging it in sends a detection pulse to the camera to “wake it up.” Step Two happens when the “detection pulse” voltage crosses a resistive element at the camera, establishing a power requirement to the PoE source. Step Three: Power flows from the PoE source to the camera at the “established level,” which is also a safety level. Dramatic increases above this level or exceeding what the switch port can supply, will shut down the camera. Each step has a potential impact on system operation. First is the action of the detection pulse being received by the camera. The standard establishes a range for output voltage of 37 to 57 voltage. However, differences exist in the amount of power that is received by a device. These are defined in the differences between 802.3af and the higher powered 802.3at. If cable resistance is too high, due to the type of cable, length of cable and most often any breaks for splices, the required voltage will not be achieved and the device will not turn on. To avoid the PSE from continuously providing power to a device or providing power when a device is not connected, the PSE will shut down power if a response if not received within 40ms. In our case, the proper detection pulse voltage has been received but again due to high cable resistance, the demand placed upon the switch’s PoE is higher than it was programmed or is capable of providing. In this case, the port power will be also shut down. "We have a PoE source in the form of a network switch, an Ethernet cable and a PoE camera.." Next, the camera is turned on and powered, but intermittently shuts down. This is the biggest reason for camera defective claims and manufacturer’s service department claims that nothing is wrong with the camera. The reason for this is most likely all the additional features that have been added to cameras in recent years. These include functions like Day/Night, Auto Back Focus, LED lighting, and PTZ operation. At the start of these functions a power surge occurs, which is higher than the power required to maintain operation. If this power level is higher than that established during start up or occurs for a longer than 40ms duration, the switch port will shut down. Once the port is shut, power is no longer available. Worse, as there is already a physical connection in place between the switch PoE port and camera, the detection pulse will not be regenerated and the camera will remain in the off condition. The solution is to reset the process by turning the port off and on, or simply unplugging and plugging the Ethernet cable back in. Unfortunately, until this occurs the camera is no longer functioning. Why should any of this occur when you read the camera manufacturer’s specifications and program the switch port to provide the proper power? Normally this should be all that is required. But take into consideration that camera specifications cannot predict the state of your transmission media, or the amount and ability of a switch to provide PoE overheads to handle requests for more power and surges. Camera manufacturers do not indicate camera surge power requirements. Fully loaded network PoE switches operating at the limit of their PoE power budgets are most likely to exhibit these “camera failures.” The important point is to determine the actual PoE system requirements and not just those of individual cameras, and don’t send cameras back for repair until you are absolutely certain it is the camera.
The advent of IP security cameras has resulted in the need to maintain existing coax cable for networking applications Transmission of video and PoE power for IP security cameras over infrastructures can be confusing. Network infrastructures are designed using twisted pair cabling that we refer to as CAT (short for Category) cable, also referred to as UTP (Unshielded Twisted Pair). Security systems, coming from an analog environment, have historically transmitted over coax cable, and with the use adaptors can transmit over CAT cabling, which can be further broken down into single pair twist and untwisted applications. Cabling shares one, often misunderstood commonality. Any physical medium has a form of resistance to any element carried on that cable. With regard to network transmission over CAT 5 and greater (5e, 6, 7), there is a distance limitation of 328 feet or 100 meters. The applicable standards state that the bandwidth applied at one end of the cable at 10/100/1000 (1G)Mbps will be realized at the other end. This is also where we find the first limitation. At this same 328-foot distance there is a loss of PoE power. 802.3af or 15.4 watts is a value realized only at the PoE source. Under the standard, after traveling through 328 feet, the power at the camera is 12.95 watts. The same is true for 802.3at which has a source power of 30 watts and 328-foot distance power of 25 watts. The advent of IP security cameras has resulted in the need to maintain existing coax cable for networking applications. The first thing to realize is there are no standards for network transmission over coax. In reality the characteristics governing coax can be considered the opposite of CAT twisted pair cable. CAT cabling for network transmission consists of 4 wire pair, 2 of which are used for signal and PoE transmission. This ability to separate PoE and bandwidth transmitting over two pairs maximises power transmission. Coax cable, when used in the same application, is limited to a single pair – center conductor and shield. Its characteristics promote bandwidth but limit PoE transmission compared to UTP cable. I emphasize again, there are no standards for coax cable transmission. This process becomes more confusing when you realize there are various type of cables that are called either UTP or Coax. All of these cable have different characteristics that have a direct impact on their ability to transmit bandwidth and PoE. The standards for UTP transmission were set for CAT 5 (5e). Categories 6, 7 and above will tend to have lower cable resistance and longer transmission distance; CAT 3, higher resistance and shorter distance. Common types of coax cable have varying distance limitations The same applies to coax cable. Again there is no standard, the typical cable found in analog security applications is RG-59. In general, application distance limitations ran between 750 to 1000 feet, greater than the 328 network limitation. This is why extenders are required to convert from coax to UTP and to extend the signal and power range. As with UTP cable, there are two similarities. First, there are different grades of coax; second, there are different types. All these differences generally apply to cable resistance and therefore distance performance. The most common types of coax cable are: RG 59, RG 6 and RG 11 Why is this important? In general there are two reasons. The first is in specifying equipment for a video security system, you are generally dealing with existing wiring and a fixed performance requirement. It is important to know the type and condition of the wiring in order to know what system performance requirements can be met. Second is a function of understanding specifications for the transmission equipment that will be used in the infrastructure. As noted, when maintaining coax, the use of coax-to-Ethernet convertors/extenders is required. In many cases even when UTP is used, distances over the 328-foot limit are required. A manufacturer’s product specification sheet can truthfully state their products can perform at 100 Mbps, they can handle 802.3at 30 watts and they can transmit distances up to 6,000 feet. However these must be viewed as separate performance claims. The key word is separate. Notice in these statements there is nothing that ties 100Mbps and/or 30 watts (these are examples only) and claimed distance of 6,000 feet together. Neither is the type of cable used indicated. By themselves, each individual claim is truthful; however, applications require they work together, and this is usually not the case. Many times it is difficult to read between the lines of manufacturer’s specifications. Failure to do so can cost additional time, money and even lead to removing the infrastructure itself. There is a simple answer. Call the manufacturer and have them confirm that their solution will perform as required for your specific application. If necessary, ask for proof that they have conducted testing to support their performance claims. Infrastructure is confusing, and you don’t need to be an expert, you just need to ask the right person(s) the right questions.
Any part of a transmission infrastructure has a dramatic impact on system performance We often view network switches as transparent transmission products. What goes in comes out. In reality, nothing is further from the truth. In this article, Neil Heller - Vice President, Vigitron, Inc. highlights that any part of a transmission infrastructure has a dramatic impact on transmission and, therefore, on system performance. At the very least a network switch can be viewed as a piece of wire. Wire has resistance and as such an effect on bandwidth. In previous articles we have discussed how IP video is transmitted as individual packets or video frames. Further, the size of the frame for IP security cameras is based generally on the megapixel size of the camera. The higher the camera megapixel size, the greater the transmitted packet. However, network switches are built for data applications. Their primary function is to pass data in the most reliable and fastest way. While IP video can be considered data, there are large differences between a packet size for word files versus video files. The latter is much larger. The focus of network switches on non-video applications is clear when you know that switch quality testing is done at 64bytes, and a smaller megapixel camera will require at least 1024 bytes. The largest packet size for network switches is about 1518bytes or about a 2-3 megapixel camera. Larger packet sizes that can yield up to 9600 bytes and result from larger megapixel cameras or low-compression formats such as MJPEG are not taken into consideration. Factors affecting bandwidth are not standardized for network switching. In many cases, they are even difficult to realize when reviewing a product’s specification. However, they can make a critical difference in the operation of your IP video security system As a result, most network switches limit their packet size at 100Mbps to 1518bytes. But wait, you just read your switch specifications and it clearly states it handles Jumbo frames or packets up to 9600 bytes. A closer look shows that statement is true provided the switch bandwidth is set to 1Gbytes (assuming your switch has 1Gbyte capacity). However, there’s more. Almost every IP network security camera outputs at 100Mbps? In networking, you must match transmission ports speeds. Failure to do so will cause video frames to be dropped. So the 100Mbps output from the camera must be matched to a 100Mbps network switch port speed. Now we have a problem, particularity with megapixel cameras and high packets (or video frames) transmitted per second. What is the problem? I recently heard it best expressed as attempting to sip a thick milk shake through a straw. Transmission can be significantly slowed. Bandwidth is reduced, and the higher the camera bandwidth the more resistance. Image-wise, the picture will look fuzzy and out of focus. There is another internal bandwidth consideration. It is called switch fabric or throughput. This is the buss that connects all the port switch ports. Again, this factor highlights the difference between switches designed for data and those that can handle video. The switch fabric bandwidth must be at least two times the sum of the highest total port bandwidth. The consideration here is the number of connected ports. In data applications not all ports are generally used; and, if they are, not at their highest bandwidth capacity. This is not case for IP Video. The result is video looks good until you connect a certain number of ports, and then things slow down. It’s similar to the number of cars on a highway as rush hour traffic builds. Eventually everything just stops. It may surprise you that the items we discussed are not standardized for network switching. In many cases, they are even difficult to realize when reviewing a product’s specification. However, they can make a critical difference in the operation of your IP video security system. See related articles: Networking Basics for Security Professionals: Network switches face PoE challenges related to IP video How bandwidth requirements guide selection of network switches Bandwidth challenges can impact your video surveillance system
Just because a switch port is capable of handling a certain power level does not mean power is actually available Are network switches really designed for IP video security? The simple answer is no. As video security migrated to IP, a major concern for video security personal was the future of their positions in regard to system specification and control. After all, networks are networks, and they are under the control of IT directors. However, as transition occurred and the demands of IP video security grew, it became apparent that database networks don’t directly translate into IP video applications. One example is the Power over Ethernet (PoE) aspect of network switches. Too often, a technical call to a camera manufacturer will result from random shutdowns. If the response turns towards the power source, namely the switch’s PoE port, the typical answer is to read the power specifications -- 802.3af (15.4 watts) or 802.3at (30 watts). This is the first problem, the misinterpretation of the actual port power. Just because a switch port is capable of handling a certain power level does not mean power is actually available. To further confuse matters, most switch specifications only provide an overall power figure. In operation, some power must be allocated to the switch functions with the remaining power divided among the ports. Next is how the switch allocates this power. In general, it can one of three ways. Activate PoE and the available power is allocated across all ports, or must be programmed to each port. In the first case, it is unlikely that full PoE class power can be achieved at any of the ports. In the second, required power levels can only be achieved until the PoE budget, or available PoE, is exhausted, thus leaving some ports without any power. The third method is often reserved for the most expensive switches and provides at least full 802.3af power to all ports, with the ability to allocate up to 30 watts to some ports. In network PoE switches, the most expensive components are those providing PoE power. As IP cameras power requirements continue to increase, the ability of network PoE to meet the needs of IP video systems will continue to diminish Simply put, there are no standards for the allocation of PoE power. There are other considerations. In most data applications, the surge power required to turn on PoE devices or applications in working PoE devices is limited. This isn’t the case for IP security cameras. Day/night, LED, autoback focus and the PTZ startup all require large power surges. In the case of PTZ, when power is applied, the dome goes to a reference zero position drawing excessive amounts of power. If a system uses several PoE domes, this can actually result in damaging a switch’s power supply. The following is a specification for a typical Layer 2 network switch. Upon first reading, you might believe that this switch has the ability to provide a full 15.4W (802.3af) to all 24 ports. But, look carefully. Here is the complete switch specification with regards to power. Power Over Ethernet PoE Standard IEE 802.3af Power over Ethernet/PSE PoE Power Supply Type End-Span PoE Power Output Per Port 48v DC, 250mA. Max 15.4 Watts Power Pin Assignment 1/2 (+), 2/6(-) PoE Power Budget 380 Watts Max Number of Class 2 PD 24 The wording indicated that all ports are capable of handling 15.4W (PoE Power Output), but does not state that all ports provide 15.4W at the same time. The PoE Power Budget is 38 Watts, but there is no indication of the power required for overheads. The most interesting specification is the Maximum Number of Class 2 PD. Class 2 is 6.49W, and the specification clearly states that the maximum number of Class 2 PDs (cameras that can be powered) is 24, but according to the specification only at Class 2. In general, network switches offer no protection other than main power fusing that will render the switch inoperative. Further, because network PoE switches conform to the safety aspects of 802.3, large surges will shut down PoE to a camera without the ability to restart. In these cases, the switch can be damaged beyond repair or the individual camera taken off line. Either results in lost recording and costly service calls. As IP cameras power requirements continue to increase, the ability of network PoE to meet the needs of IP video systems will continue to diminish. Too often, a misreading of network switch specifications leads to the selection of switches that will only ensure camera shutdowns or unnecessary returns of properly working cameras to their respective manufacturers. System users may learn only too late that their selected switches, despite their “brand names” or reliable operation in data networks, must be replaced or augmented with separate PoE midspans.
Often our selection of a network switch is based on price or major brand names, both of which can lead to problems Networking Basics for Security Professionals: How bandwidth requirements guide selection of network switchesIf a network switch looks like a network switch, is it a network switch that will work for IP video security applications? The surprise answer is “not necessarily.” There are major differences between the network switch performance required for data applications such as word processing, accounting and web browsing and that required for IP video for security applications. These differences have a major effect on performance. Often our selection of a network switch is based on price or major brand names, both of which can lead to problems. The bandwidth output of IP security cameras is 100Mbps; in networking, output speed must be matched by input switch port speed. However, in most cases switch ports operating at 100Mbps limit their packet size or video frame in our case to about 1518 bytes. This is equal to about a 2-3 megapixel camera. The higher the pixel count, the larger the video frame and higher the number of bytes contained in that frame. Packet sizes greater than 1518 bytes are generally referred to a Jumbo Frames. The inability of a port switch to handle Jumbo Frames can result in blocking information from higher-end megapixel cameras starting at about 3 megapixels. To handle larger megapixel cameras, a network switch must be able to be programed for up to 9600 bytes when the port bandwidth is 100Mbps. Network switches that provide for 1 Gigabyte port bandwidth settings provide the ability to resolve Jumbo Frames; however, the mismatch between the 100Mbps output of the camera and input of the switch is often overlooked. It’s a mistake to interpret that the switch will have this same ability at 100Mbps. Faulty settings applied to high-megapixel cameras can result in distorted video or inability to pass video at all. When addressing the actual number of usable ports, port packet handling and switch fabric bring up the point that there are no standards for these features The second consideration is called either throughput or switch fabric. This defines the bandwidth that connects all the switch ports. In many data-only applications, the maximum port bandwidth is never achieved. In order to ensure that high-bandwidth video is passed, the switch fabric must at least two times the total bandwidth of all the ports. For example, a 24 port Gigabyte switch needs to have a switch fabric of 48 Gigabytes. Switches with less can exhibit video quality issues if all ports are used, which is usually the case with IP video applications. The third area that is often overlooked is the actual number of ports. A switch advertised as a 24-port does have 24 actual ports. However, that doesn’t mean you can use all 24 ports. First there is the consideration of how the switch is positioned within the network. Often this requires an up and downlink. As such, two ports are lost and reduces the usable ports to 22. Some manufacturers realize this and limit the application of power over Ethernet (PoE) to only 20 ports or the total number of ports minus 2. This also makes their PoE specification look better, but denies you of the use of two ports. When addressing the actual number of usable ports, port packet handling and switch fabric bring up the point that there are no standards for these features. In a competitive network switch market, manufacturers design products to meet the most competitive pricing for the majority of applications. Our market’s major concerns are large packets, video frames and high internal bandwidth. These remain minority concerns with the majority of network switches that don’t cater to video security IP applications.
Too often we make the assumption that networks designed for data communication are the same as those for IP video Networking Basics for Security Professionals: Bandwidth challenges can impact your video surveillance systemToo often as we continue on the transition from analog to IP video surveillance, we make the assumption that networks designed for data communication are the same as those for IP video. In fact, they are very different. While we focus on camera, NVR and VMS specifications, we often overlook that in reality it is the transmission of IP video that determines quality and performance. We shouldn’t be quick to blame system failures on the products connected to either end of the transmission line when it the transmission itself. Most of the considerations and differences between data networks and video security IP networks center around two general areas -- bandwidth and PoE, power over Ethernet. Here let’s consider bandwidth. Security transmission from cameras through a network is usually at transmission speeds of 100Mbps. The first rule is that transmission speeds within the network must be matched. So a camera with an output of 100Mbps must be connected to a switch port set at 100Mbps. We should also not assume that how we transmit the signal doesn’t affect bandwidth – it does. Related to total bandwidth available for transmission, we should not conclude that if our camera transmits images at 1Mbps, we can feed 100 cameras into the transmission line. Any physical transmission media has internal resistance. When we deal with the Ethernet standard, the transmission distance is fixed at 328 feet or 100 meters, and the performance standards are set to that distance based on the resistance of Cat 5 cabling. Shorter distances do not negatively impact performance; longer distance do. However, distance isn’t the only factor. IP transmission is interactive. Multiple factors contribute to affecting performance. To better understand, let’s examine IP video. Bandwidth limitation can make an image look pixelated or the NVR not recognizing an image There is an important similarity between analog and IP video in that both are transmitted as individual pictures. IP video is transmitted in packets referred to as Video Frames. Both are similar in that the number of these images per second determines the fluidity of movement. The key difference is that while video comprises 100% of the analog frame, only 50% of bandwidth or less is reserved for the IP video image. The other 50% or more is taken up as packet overheads. This is the information that directs the video image to a destination and, if required, directs responses back to your computer. So for IP video, we start by losing 50% of our transmission space. The second consideration is the size of the packet. As megapixel images increase, so do their packet sizes. Data communications were designed for smaller data applications such as Word and accounting documents. In fact, almost all data products determine their performance specifications based on a packet size of 64bytes. Even the smallest 1 MP camera will have a packet size of at least 1024 bytes. Standards and testing for data packet transmission end at around 1518 bytes or about 2 to 3 MP cameras. Above that, packets are called Jumbo Frames. They exist from about 1518 to 9600 bytes. In general, megapixel cameras with 3MP and greater exist at Jumbo Frame packet sizes. Two more considerations are added to the several others affecting bandwidth. One is how the type of codec used affects image size. The general rule is that H.264 requires the smallest bandwidth and MJPEG the highest. Next is the number of images per second: More images requires higher bandwidth. Consequences of bandwidth limitations vary. They can result in an image looking pixelated or the NVR not recognizing an image and displaying a dark screen. Depending on the number of bandwidth requirements in your system, the problem may not remain constant and can change among cameras depending on which camera’s bandwidth dominates at a given time. The takeaway is that equipment designed for standard data transmission simply does not meet requirements for IP video transmission.
Vigitron, Inc, the manufacturer of complete networking solutions designed for security applications announces major new product releases for ISC West 2019. These products cover areas of PoE Midspans, Network Health Monitoring, Testing and Installation Tools, Building Infrastructure and Network Switching. Reliable And Cost-Effective Products “Vigitron continues to lead as a comprehensive source of networking solutions,” stated Neil Heller, Vigitron’s Vice President of Business Development. “Several years ago, we expanded our engineering team to include software and firmware developers in addition to our existing hardware engineers. We continue to work with major hardware providers in the areas of IP cameras, access control, and LED to develop products resulting in the most reliable and cost-effective performance. “In addition to our advanced engineering and product development, Vigitron continues to lead in the support areas with our Design Center team providing dealers with complete bills of materials designed for their specific applications.” Vigitron’s new products will be on display at ISC West booth # 8130, April 10-12, at the Sands Convention Center, Las Vegas.
GNM Hough Inc., a systems integrator and dealer in South Florida specializing in commercial electronic security systems, has selected Vigitron, Inc. as their network supplier. Gina Hough, GNM Hough Inc.’s President commented, “In the past, we’ve installed many different types of network equipment from different manufacturers, only to have on-going service and performance issues.” Cost-Effective Solutions “When we standardized our offering with the Vigitron product line, we began to see a significant drop off in service calls and an increase with customer satisfaction due to the performance and stability of the surveillance systems we’ve installed. As we move forward trying to capture more of the aging analog camera market, we know that we have the best total solution from our partners at Vigitron with their innovative products and solutions.” Neil Heller, Vigitron’s Vice President noted, “As the only full product supplier of network equipment, we value our relationship with GNM Hough Inc. Backed by extensive inter-operational testing of major camera, access control, and security lighting, we work with dealers to assure the most reliable and cost-effective solutions. Our main goal is to reduce the potential for expensive and time consuming after sales service calls and system down time. We are pleased to offer our Design Center Services, staffed by trained network engineers with no cost or obligation.”
Vigitron, global manufacturer of complete networking solutions, announces an integration platform for its line of network switches with the SeeTec Cayuga Video Management Software. The integration will allow for status checking and health monitoring of connected devices to Vigitron’s network switches that are operating on the VM software by the German SeeTec GmbH. Working in conjunction with Vigitron’s unique ability to monitor connected devices and automatically establish reconnections, users of SeeTec Cayuga will be able to program custom responses and alerts. The result is a system that will assure comprehensive recovery and protection. Vigitron-SeeTec Integration Platform Network performance and conductivity are key factors in any security system"“Many times, software is wrongly pointed to as a cause of failure,” states Neil Heller, Vice President of Business Development for Vigitron. “Network performance and conductivity are key factors in any security system. The ability of SeeTec Cayuga to monitor the network, identify the source of a problem, and correct them will directly contribute to fewer system down times while at the same time increasing system reliability. Vigitron is pleased to have SeeTec as a partner in these technical advancements.” IP Video Management “It is interesting to see how IP video management has evolved over the years. Incorporating status messages of hardware components other than cameras into the user interface of Seetec Cayuga is the next step to give administrators yet a better overview over the overall health of their installation,” says Daniel Bechler, Head of Project Engineering and Alliances at SeeTec. He adds: “This way we are getting closer to our goal of making the VMS the universal information hub for viewing, administration and monitoring.” Vigitron products are sold and serviced by Barox Communications under a partnership agreement with Vigitron Central Europe. The integration and its benefits will be part of Barox’s European training efforts.
Vigitron, Inc., the provider of network solutions designed for IP/PoE applications, announces the appointment of Ms. Valorie Windsor as Mid-West Regional Sales Manager. In her capacity, Ms. Windsor will be responsible for managing Vigitron’s sales in a region extending from the Canadian to Mexican boarders. Ms. Windsor brings to Vigitron over 20 years of sales and business development experience in various aspects of the physical security with emphasis on video surveillance having held several roles with industry giants such as Pelco/Schneider Electric, Panasonic, and Nice Systems. Ms. Windsor’s experience includes a start up as a co-founder of CoVi Technologies. Ms. Windsor has wide knowledge in many forms of transmission include fiber optic/broadband connectivity. Free Of Cost Network Design Services “The addition of Ms. Windsor as the Mid-Western Regional Sales Manager adds to the recent appointment of Mr. Allan Stone as Eastern Regional Sales Mangers, continuing Vigitron’s goal in expanding our sales and services,” noted Neil Heller Vigitron’s VP of Business Development. “With over 200 IP/PoE products providing complete network solutions, Vigitron stands apart as the only manufacturer which supports customers with free and without obligation network design services staffed by trained engineers and configuration services.”
Vigitron, Inc, the provider of network solutions for security applications announces the addition of Mr. Allan Stone as Eastern Regional Sales Manager. Mr. Stone has over 30 years of experience in the security industry building relationships with end users, dealers, and distributors. “We are pleased Allan has elected to join the Vigitron team,” stated Neil Heller, Vigitron’s Vice President. “His extensive experience with developing sales channels will be critical as Vigitron grows in the areas of firmware and software in addition to our extensive industry leading categories of IP network products. Adding Allan to our team reflects Vigitron’s continuous growth.” “I am excited to join Vigitron as their Eastern Regional Sales Manager,” stated Allan Stone, “Vigitron has dedicated their engineering to building transmission/infrastructure products from day one. Vigitron specializes in products that are purpose built for IP Video Projects that require infrastructure to support all of that video data. It will be a pleasure to bring to you a quality product, one that is stable and has self-diagnostics built-in to insure reliability. Allow us to show you the difference.”
The Vigitron Vi3202 provides up to 60W PoE with a built-in coax extender for up to 5,000 feet At ISC West 2017, Vigitron will introduce its Vi3004/Vi3004LV and Vi3202, designed for easy conversion of existing analog systems to IP. Vigitron Vi3004LV The Vi3004LV is a 4-port Layer mini network switch providing two Fiber and two UTP ports. It can be used for either single cable runs of fiber or UTP. The Vi3004/Vi3004LV takes the place of network switches eliminating their costs with a direct connection to servers operating video management software or network video recorders. It can also be used in conjunction with network switches extending the capacity of individual ports. The Vi3004/Vi3004LV models can be powered by 24VAC or 120/240VAC and provide up to 90W of PoE when the UTP ports are used to power up to two cameras. “The Vi3004 series addresses the industry trend for installing both a spot and PTZ camera for parking lot and perimeter locations”, stated Neil Heller, Vigitron’s VP of Business Development. Heller went on to say: “almost every analog PTZ installation uses a 24VAC as its primary power. The Vi3004LV uses the same power source to provide up to 802.3at PoE 30W power for spot cameras and 60W for IP based PTZ cameras. The drop-and-insert functionality further reduces installation costs by eliminating the need to home run every single location.” Vigitron Vi3202 The Vi3202 provides up to 60W PoE with a built-in coax extender for up to 5,000 feet. “Analog PTZ have two features in common, they are powered by 24VAC and are transmitted over coax for distances usually between 750 to 1,000 feet. This is 2.5 to 3.5 times greater than standard Ethernet transmission of 328 feet.”, stated Heller. “The Vi3202 addresses all of these by providing a drop-and-insert solution that eliminates the need for new power sources and wiring providing transmission over coax over 5,000 feet. Furthermore, the size of Vi3202 easily fits in enclosures of many PTZ mounts, further reducing costs by eliminating the need for extra cost environmental housing.”
The new series also includes a low cost, high PoE switch and an unique Layer 3 core fiber switch At ISC West 2017, Vigitron will introduce the first series of Hybrid managed network switches designed for security applications. The new MaxiiNet™ Hybrid series adds to the existing managed switch product line to further address the needs of security systems. MaxiiNet™ Hybrid Series The Hybrid series combines Extended Distance UTP, Coax, single pair wire, and Fiber with standard UTP/PoE ports, providing complete solutions for security transmission into a single 1U high package. PoE up to 36W addresses the requirements of the connected device start-up and accessory functions such as day/night, reducing potentials for port shutdowns that render connected devices from going offline. The PoE outputs from two ports can be combined to provide power to devices requiring more than 30W such as the 60W PTZ domes. The new series also includes a low cost, high-PoE switch and an unique Layer 3 core fiber switch. This new series not only focuses on the need for every increasing PoE, but also providing a 685W power supply to provide a 550W PoE budget. Each will be able to provide up to 36W with all ports operational. PoE port power can be combined for powering 60W PTZ domes with heaters and blowers. PoE Management “This new network switch product series addresses the needs of security users by focusing on simplifying network setup and operation, while providing the power and management required for PoE,” stated Neil Heller, Vigitron’s Vice President. “In addition to PoE management,” Heller continued, “operation and monitoring can be achieved by the switch’s easy to use Graphical User Interface. The latter prevents hacking by isolating the device’s IP address. Finally, by combining network switching, PoE Midspan management, and extenders in one package, a significant cost and space saving is achieved.”
The Design Center will provide support for developing networking infrastructure solutions Vigitron, a provider of networking infrastructure solutions for security applications and Barox Kommunikation, a company for transmission technology, announce the establishment of a Design Center service operating under both companies collaborative group, Vigitron Central Europe. Support For Developing Networking Infrastructure The Design Center will provide support for developing networking infrastructure bill of materials designed for specific applications. It will use Vigitron’s inter-operational data based developed from testing hundreds of security products in the areas of IP camera, access control, PoE lighting, and emergency response systems. The data base provides data on actual equipment performance such as bandwidth and PoE device requirements operating on standard and extended physical transmission mediums. The service is staff by trained engineers and will be provided free of charge with no obligation. Direct Access And Optimization Of Vigitron Products “Networking infrastructures are unique and individual for every application”, stated Neil Heller, Vigitron’s VP President of Business Development. “You cannot rely on drop down menus as every component within an infrastructure changes the total infrastructure. Using the Design Center, individuals will be able to interact with knowledgeable engineering personnel. Establishing the Design Center in Switzerland will provide more immediate and local access throughout Europe, U.K., Africa, and the Middle East.” “As Vigitron´s partner in Central Europe, we are opening a Design Center,” explains Rudolf Rohr, CEO of Barox Kommunikation. “This gives the European customers the chance to have direct access to Vigitron products and have them optimized for the European market. Many of the big challenges in Europe compared to the US market are the huge amount of 2 bell (wire) installations.”
Vigitron will be able to provide Paxton's sales channel with its Design Center services to offer reliable networks Vigitron Inc., the leading manufacturer of infrastructure solutions for analog, IP, and HD systems, is pleased to announce it has completed inter-operational testing for IP/PoE based products from Paxton Access Inc., market leader in IP access control, door entry and building intelligence systems. Vigitron will be able to provide Paxton's sales channel with our Design Center services in order to offer the most cost effective and reliable networks designed specifically for Paxton Access applications. Growing Migration Of Security To PoE Driven IP Networks "Adding Paxton to our growing list of partners is another indication of the growing migration of security to PoE driven IP networks," stated Neil Heller, Vigitron's Vice President of Business Development. "Access control is particularly well suited for IP transmission powered by PoE as it significantly reduces installation cost by reducing the amount of wiring." Heller continued, "The key element is Vigitron's ability to continuously monitor the network to assure communications are valid and affect unattended reconnections in the event communications are lost." Paxton Net2 Access Control - IP Based Solution Chris Wilson, Product Manager for Paxton, Inc. says: “The security market is rapidly adopting PoE technology to continue the exploitation of merging technologies and systems for greater efficiencies and convenience. Paxton provides Net2 Access Control, an IP based solution with an extensive hardware and software feature set. We are pleased to work with Vigitron to offer our customers the ability to install our solution in those challenging infrastructure opportunities.”
The combination of Superior Essex cable and Vigitron products provided power higher than 802.3at over distances of up to 1,200 feet Vigitron, Inc., a leading manufacturer and provider of analog, IP and HD transmission solutions, has completed inter-operational testing with the Superior Essex PowerWise™ Category 5e+ 4PPoE 22 AWG cable. The combination of Vigitron products and Superior Essex cables results in the ability to provide 802.3af Class 2 Power-over-Ethernet (PoE) for distances up to 3,000 feet, Class 3 for distances up 2,500 feet, and 802.3 Class 4 up to 1,500 feet. “We find the greatest significance in applications requiring camera power higher than 802.3at,” says Neil Heller, Vigitron’s Vice President of Business Development. “This includes cameras which are generally referred to as 60 watts and power all functions, including heaters and blowers using PoE. The combination of Superior Essex PowerWise cable and Vigitron PoE infrastructure products resulted in achieving distances up to 1,200 feet, decreasing installation costs while maintaining central control over all camera functions. While focusing on higher powered cameras, we shouldn’t overlook similar applications such as the growing number of static outdoor cameras with built in heaters and blowers that operate at full 802.3at power levels of 25.5 watts.” Reliable PoE Cabling And Infrastructure Solutions “Vigitron’s success with the PowerWise Category 5e+ cable in Power-over-Ethernet applications is a testament to the real value of this product in terms of its energy efficiency and overall performance,” says Amir Sekhavat, Global Director of Premises Copper products at Superior Essex. “Partnering with Vigitron ensures our customers are receiving the exceptional PoE cabling and infrastructure solutions they require to exceed the demands of their present and future installations.” Vigitron will be incorporating Superior Essex into its industry-leading Design Center Services, which provide the most cost-effective and reliable infrastructure solutions staff of trained engineers. This service is provided free to dealers and distributors and without obligation.
Vigitron will provide infrastructure equipment for PCSC’s growing line of IP/PoE based access control products PCSC, a provider of state of the art access control systems, and Vigitron, Inc., a global leader in analog and IP infrastructure transmission solutions, have announced the expansion of their relationship to form a world-wide partnership. Under this agreement, Vigitron will provide infrastructure equipment for PCSC’s growing line of IP/PoE based Access Control products, as well as, service, training, and technology sharing. Strengthening Business Relationship “Our mutual partnership is a clear indication of the rapid expansion of access control systems using IP and PoE,” stated Neil Heller, Vigitron’s Vice President of Business Development. “This agreement will assure PCSC customers have reliable and cost effective infrastructures designed specifically for their applications and backed by the industry’s longest warranty. In return, PCSC’s long standing and deep knowledge of the access control market and technology is providing Vigitron the ability to expand its product lines and knowledge base. This partnership mutually benefits both companies and our customers.” “We’re excited to further strengthen our business relationship. The continued convergence of the IP/IT world with physical security demands integrated solutions. We recognize this need, and have been at the forefront of offering IP based security products to those professionals,” said Mas Kosaka, President and CEO of PCSC. “We have found Vigitron’s PoE devices complement our IP based access control solutions, strengthening our Fault Tolerant architecture offering. Enabling power and communication to all LAN devices, whether it is video or entry point hardware is advantageous. Leveraging IP/IT infrastructure means eliminating the need for local power, this consolidates and saves labour costs and reduces install time, all while being more scalable.”
Under the agreement, Vigitron will also provide service, training, and technology sharing for PCSC products PCSC, a provider of state of the art access control systems, and Vigitron, Inc., a global leader in analog and IP infrastructure transmission solutions, have announced the expansion of their relationship to form a world-wide partnership. Under this agreement, Vigitron will provide infrastructure equipment for PCSC's growing line of IP/PoE based access control products, as well as, service, training, and technology sharing. IP And PoE Convergence "Our mutual partnership is a clear indication of the rapid expansion of access control systems using IP and PoE," stated Neil Heller, Vigitron's Vice President of Business Development. "This agreement will assure PCSC customers have reliable and cost effective infrastructures designed specifically for their applications and backed by the industry's longest warranty. In return, PCSC's long standing and deep knowledge of the access control market and technology is providing Vigitron the ability to expand its product lines and knowledge base. This partnership mutually benefits both companies and our customers." "We're excited to further strengthen our business relationship. The continued convergence of the IP/IT world with physical security demands integrated solutions. We recognize this need, and have been at the forefront of offering IP based security products to those professionals," said Mas Kosaka, President and CEO of PCSC. "We have found Vigitron's PoE devices complement our IP based access control solutions, strengthening our Fault Tolerant architecture offering. Enabling power and communication to all LAN devices, whether it is video or entry point hardware is advantageous. Leveraging IP/IT infrastructure means eliminating the need for local power, this consolidates and saves labor costs and reduces install time, all while being more scalable."
Vigitron to provide reliable network switching and PoE products as part of PCSC’s IP access control solutions PCSC, a state-of-the-art designer and manufacturer of access control systems and Vigitron, Inc., a global leader in analog and IP infrastructure transmission solutions, have announced a working partnership for Vigitron to provide reliable network switching and PoE products as part of PCSC’s IP access control solutions. Improving Fault Tolerant Architecture With Vigitron: “We have found Vigitron’s PoE devices complement our IP based access control solutions, strengthening our Fault Tolerant architecture offering,” said Mas Kosaka, President and CEO of PCSC. “Enabling power and communication to all LAN devices, whether it is video or entry point hardware is advantageous. Leveraging IP/IT infrastructure means eliminating the need for local power, this consolidates and saves labor costs and reduces install time, all while being more scalable.” “We’re excited over the synergy that stems from this partnership,” said Al Portal, PCSC’s Director of Sales, Americas. “Quality meets affordability with Vigitron products. Anytime we can offer our business partners additional product IP solutions that meet our vision of tomorrow’s access control standards, it is a win-win for all.” “We are pleased to have been selected by PCSC,” stated Neil Heller, Vigitron’s Vice President of Business Development, “The partnership is based on Vigitron’s unique product features which offer stable and reliable PoE power with the ability to respond to the high surge requirements of door strike and mag locks. PCSC products, such as their IP/PoE patented ‘Fault Tolerant’ system, will be integrated into Vigitron’s Design Center service to provide expanded coverage for PCSC’s sales channel and to assist with the design of their IP-based infrastructure requirements.”