NVR bandwidth: recording, playback and decoding are different
Map each flow through the network interface it actually crosses.
Updated
Principle and limits
Incoming recording traffic, outgoing live/playback streams and local display decoding are separate resources. A network port’s link speed does not prove the recorder can ingest, write or decode that much video. Draw the topology before adding rates: traffic may cross an uplink, stay within an integrated PoE switch or use a second interface.
Worked example
In a simplified layout, 16 cameras ×4 Mb/s give 64 Mb/s incoming payload. Four playback streams ×4 Mb/s plus an 8 Mb/s export give 24 Mb/s outgoing payload. On a full-duplex link, compare each direction with its own limits; an internal shared processing limit may still constrain the total. Add protocol overhead and measured peaks before acceptance.
Installation and acceptance
Run the intended camera wall, playback and export together while recording. Inspect missing segments, dropped frames, decode load and interface errors. Record stream resolution, codec and frame rate alongside bitrate. A smaller display substream can reduce client load only if supported and selected; it must not silently reduce the required evidence stream.