Direct answer
Count camera ingests, concurrent viewer outputs and every stream that must be decoded or transcoded. Size for the peak combination plus restart and failover headroom, not the average dashboard.
Why this happens
A relay-only path is usually limited by network and session count, while transcoding adds decoder, encoder, memory and thermal constraints. Multi-camera grids multiply the load quickly.
Browsers normally need a gateway that converts the camera feed into a web-native delivery path.
A controlled test
Build a small load model, then validate it with the real codec, resolution, frame rate and viewer count.
Change one variable at a time. Keep the camera model, firmware, endpoint and account recorded; then test network reachability, protocol response, media transport and decoding as separate layers.
Use a dedicated view-only account and a trusted local diagnostic tool. Redact credentials, private addresses and identifying data before sharing output.
Diagnostic sequence
| Check | Action | Evidence of progress |
|---|---|---|
| Ingest | Count persistent camera sessions and bitrates. | Source bandwidth and camera limits are known. |
| Fan-out | Estimate peak viewers per output. | Egress bandwidth is bounded. |
| Compute | Count simultaneous decode and encode operations. | Hardware and software capacity are tested. |
| Headroom | Test restart, reconnect storm and one failed node. | The service recovers without overloading cameras. |
Evidence to keep
Track p95 CPU, memory, egress, startup time and reconnect rate during a realistic peak test.
Boundary and safety note
Do not publish a capacity number without the codec and workload assumptions that produced it.
For remote viewing, use a managed VPN instead of exposing RTSP or camera administration ports directly to the public internet.
SmartRTSP
SmartRTSP is a camera-focused RTSP and ONVIF viewer for Apple devices, Windows and Android. It fits direct viewing, discovery and multi-camera checks; keep a dedicated NVR or VMS when continuous recording, evidence export or centralized enterprise controls are required.
Frequently asked questions
How many cameras can one gateway handle?
There is no useful universal number; it depends on bitrate, codecs, transcoding, hardware and viewer fan-out.
Does passthrough remove all compute cost?
It removes most video encoding cost but still uses network, memory, session and packaging resources.
Why test reconnect storms?
A gateway restart can cause every camera and browser session to reconnect at once, creating a peak far above normal load.
Primary references
- FFmpeg — RTSP protocol options and examples
- IETF RFC 7826 — Real-Time Streaming Protocol 2.0
- CISA — Secure by Design guidance
Related SmartRTSP guide
Open related guideEstimate sessions, bandwidth, decoder surfaces and failure headroom before putting many camera feeds behind one gateway.