Differences and application scenarios of RTSP, RTMP, and GB/T 28181
Positioning comparison
| Protocol | Main uses | Typical scenarios | Transport layer |
|---|---|---|---|
| RTSP | Real-time stream control and on-demand | NVR gets IPC stream, player preview | TCP/UDP |
| RTMP | Internet live streaming | Push to video account/live streaming platform | TCP |
| GB/T 28181 | Domestic security networking standard | Connect to public security/traffic police/education supervision platform | TCP/UDP + SIP |
RTSP
The real-time streaming protocol itself is only responsible for control (play, pause, stop), and the actual media data goes through RTP. It is the most common flow acquisition method for security equipment. Common address format: rtsp://IP:554/Streaming/Channels/101 (101 represents the main stream of channel 1, and 102 represents the sub-stream). The advantage is low latency (usually 200~500ms), but the disadvantage is that the ability to traverse firewalls is weak, and direct exposure to the public network is unsafe.
RTMP
The mainstream protocol for early Internet live broadcast is based on TCP and has good penetration. Although it has been largely replaced by HTTP-FLV/HLS/WebRTC on the browser side, But the push side (device → server) is still widely used. In security scenarios, it is used when pushing surveillance images to the live broadcast platform. Note that RTMP delays are usually between 1 and 3 seconds.
GB/T 28181
Chinese national standards, based on SIP signaling + RTP media, stipulate processes such as device registration, directory reporting, real-time on-demand, video retrieval and playback. Any project that needs to be connected to the government supervision platform must basically support it.
- Requires configuration: SIP server ID/domain, SIP server address and port, device national standard ID (20-digit code).
- Equipment coding has rules, usually consisting of center code, industry code, type code, serial number, etc., and needs to be obtained from the platform.
- The most common problems during connection are Incorrect coding or Unreachable port/network segment.
How to choose
- NVR access camera in LAN: RTSP (with ONVIF automatic discovery).
- Mobile/Web remote viewing:Preferred Vendor P2P or HTTPS-FLV/HLS.
- Connect to government/industry supervision platform: GB/T 28181.
- External live broadcast: The camera/encoder RTMP streams are pushed to the streaming media server for distribution.