How it works
The formula, without the black box.
recording Mb/s = cameras × main stream; remote Mb/s = viewers × viewed stream
This estimate does not add streams that are not actually concurrent. Some systems relay through cloud services, transcode, or send multiple streams; verify the network diagram and device documentation.
Inputs that deserve a second look
- Main stream
- The stream recorded locally by the NVR or VMS.
- Substream
- The lower-rate stream normally selected for remote multiview.
- Simultaneous views
- Concurrent camera streams, not merely logged-in users.
- Upload capacity
- Measured sustainable upstream throughput available to camera viewing.
Common planning mistakes
- Adding internet upload to local recording traffic as if they share one bottleneck.
- Counting users instead of simultaneous streams.
- Ignoring recorder incoming-bandwidth and switch-uplink specifications.
- Planning at the speed-test peak with no capacity headroom.
Questions installers ask
Does 16 cameras at 4 Mb/s require 64 Mb/s internet upload?
Not for local NVR recording. It creates about 64 Mb/s of local recording traffic. Internet upload depends on what leaves the site and which stream is used.
Why add headroom?
Variable bitrate, protocol overhead, bursts, and other network traffic make a plan at exactly 100% utilization fragile.
Does this include camera-to-cloud recording?
Only if you model the uploaded stream as the relevant outgoing bitrate. Cloud architectures need vendor-specific checks.
Sources and boundaries
These links support the method or terminology. They do not turn a planning estimate into a site guarantee.
ONVIF Profile T overview ↗
Streaming/compression context.