Bandwidth Help For 80 IP Camera System

1. For bandwidth estimation, what frame rate are you using? What camera model? 1Mb/s might be sufficient, but it's not possible to tell without more information.

2. When calculating bandwidth needs, add up the bandwidth needed coming in (from cameras) and going out (to clients). Typically, bandwidth going out is fairly minimal though.

3. What do you mean by NVR recording at local base? Compared to what alternative?

4. Where is this 5MB of bandwidth? Between cameras and recorder? Or between recorder and clients? Also, do you mean 5Mb/s (bits) or 5MB/s (bytes)

For background, please read these tutorials so you can better understand key fundamentals:

• Calculating Bandwidth / Storage Needs
• Estimating Server Size

Bandwidth is used in several ways. Here are the 3 most common:

1. The NVR (VMS running on a PC) will use inbound bandwidth when receiving video streams from the 80 IP cameras for recording and distribution to clients (PC clients, mobile phones, etc...). for 1280x1024/960/720 (1-1.3MP) cameras running at 15FPS, H264 Main Profile, you will need 1.5Mbps per camera for good quality recording. Many VMSes also take a second low resolution (~CIF/D1) stream from each camera for energy/CPU efficient transmission of video to remote clients without transcoding - this will usually add another ~200kbps per camera. Overall, to be on the safe side, plan 2Mbps per camera - so total bandwidth use by the NVR receiving from all 80 IP cameras is 160Mbps.

Summary: NVR needs 160Mbps inbound/download bandwidth from cameras to NVR CONSTANTLY as you are usually CONSTANTLY recording the footage - this is nothing to do with who is watching/using the video - even when nobody is watching live/playback, this bandwidth will still be used.

2. The NVR will use outbound bandwidth to send video to clients on the local network. Most VMSes either have manual adjustments (e.g. manual steam selection for live view) or automatically throttling/stream switching features that cooperative between the local network client and the VMS server to optimize the transmission of video for live view and playback (this is VMS specific - you must check this according to your VMS). The "worst" case scenario is the VMS server sending all the streams to a local client directly connected via gigabit on the same or nearby switch - in this case the VMS server may be able to send all 80 MP video streams to the client. In this case just 1 client will consume 80x1.5=120Mbps

Summary: NVR needs X Mbps outbound/upload bandwidth up to 120Mbps per client (but normally much less) depending on how many cameras each client monitors, how much bandwidth they actually have, how the VMS is designed, etc... Total outbound bandwidth from the VMS server is the sum of all bandwidth used by all the clients connected simultaneously.

3. The NVR will use outbound WAN bandwidth to send video to clients on remote networks (central office, mobile clients, etc). Typically in this case, the remote client will have limited bandwidth, which helps to constrain the maximum bandwidth required. Assuming this, the required bandwidth is the number of remote clients * the connection speed of each client. e.g. 5 mobile clients with 1Mbps 3G connections will total use 5Mbps when they are all simultaneously connected (which is usually not the case).

Summary: the WAN outbound/upload bandwidth consumed by the NVR depends on who is remotely connected and how fast their internet connection is.

Interesting NOTE: (2) and (3) are not unique to IP camera systems - DVRs used with analogue cameras also consume bandwidth in the SAME way when you allow local and remote clients to view/playback video.

What VMS are you using? Or are you using 1 or more standalone NVRs?