When planning an installation involving multiple high-bandwidth IP cameras, often security dealers wonder “can the network handle the combined bandwidth of the X number of cameras that are going to be connected?”

First, security dealers should verify via testing that the UTP cables that will connect the IP cameras to the network switch are properly terminated and pass when tested. Assuming that the cables and connectors are good, the next step is to check the switch fabric specifications on the network switch.

The switch fabric value indicates the maximum throughput of a given switch. Let’s look at the example of a Trendnet TQ-TPE224WS 24 port switch.

This indicates that this particular switch model can process and forward 12.8 Gbps (Gigabits per second) of data. If you calculate the bandwidth of each camera and add the values, you will see that when connecting to this switch multiple mega-pixel/HDIP cameras can be connected and the switch has the capacity to handle the video data feeds.

Let’s look at an example. We are planning to install 22 megapixel cameras, each of which will output 8-12 Mbps in the H.264 compression format. The bandwidth will vary when the cameras are in use based on the camera locations, movement seen, and the lighting. Most all major IP camera vendors have some type of bandwidth calculation software which is usually available for your use on their website. So we take the maximum value, 12 Mbps times 22 for a total maximum video bandwidth required of 264 Mbps. As the Trendnet switch can process up to 12.8 Gbps, a little calculator pounding reveals that the aggregate video streams will use a bit more than 2% of the total switch fabric. So from a bandwidth throughput perspective this planned installation will work. Prudent network planners will typically calculate the expected network bandwidth and add 30% as a cushion so that the IT infrastructure devices are capable of the possible connection of additional devices.

Keep in mind that if your are going to connect an NVR/VMS server to record these relatively large video streams the recording device should be connected to one of the 10/100/1000 Ethernet ports on the switch as the 10/100 ports cannot handle the 264 Mbps combined video data streams. It’s important to note that when using cameras or encoders with H.264 compression that this format is very processor intensive. With multiple simultaneous video streams to be processed and recorded, installation companies should check with the NVR/server manufacturer to verify that their device has the processing capacity to handle the load.

The switch fabric value should always be checked whether a new switch is being installed or an existing switch is to be used. Keep in mind when connecting to a customer’s existing switch(es) the data calculations must include the client’s typical enterprise/business data load.

ADI offers a number of training opportunities throughout the year that provide more information on IP installations. Click here to check out the upcoming training events taking place at your local ADI branch.