CCTV Bandwidth Calculation: Camera Traffic, Uplinks and NVR Capacity

A practical guide to estimating IP camera bandwidth and checking switches, uplinks and NVR incoming capacity.

Start with bitrate, not megapixels

Network traffic is primarily determined by the camera stream bitrate. Resolution, FPS, codec, scene activity and configured quality influence that bitrate.

Calculate aggregate traffic

Add the expected bitrates of all cameras sharing a link. Then consider whether the link also carries management traffic, playback, client viewing or other network services.

The uplink is often the bottleneck

A switch can have many gigabit PoE ports while its uplink is slower. For example, a group of cameras may collectively produce more traffic than a single uplink can comfortably carry. Always calculate the aggregate load at each aggregation point.

NVR incoming bandwidth

Check the NVR specification for incoming bandwidth and compare it with the camera streams actually being added. Do not confuse recording bandwidth with the NVR's decoding capability.

Leave engineering headroom

Do not design a production CCTV network around the theoretical maximum. Leave room for bitrate variation, future cameras, playback and operational traffic.

Practical commissioning

After installation, verify link negotiation, switch statistics, NVR incoming traffic and camera stream settings. A design calculation is a planning tool; the live network confirms the result.