Quick Answer
| Protocol | Full Name | Purpose | Port |
|---|---|---|---|
| RTSP | Real Time Streaming Protocol | Control (play, pause, seek, describe) | 554 (TCP) |
| RTP | Real Time Transport Protocol | Data transport (video/audio packets) | Dynamic UDP (even ports) |
| RTCP | RTP Control Protocol | QoS feedback, sync | RTP port + 1 (odd) |
What is RTSP?
RTSP (Real Time Streaming Protocol) is an application-layer control protocol defined in RFC 2326 and updated in RFC 7826.
It behaves a lot like HTTP for streaming sessions: the client sends commands such as DESCRIBE, SETUP, PLAY, and TEARDOWN to tell the camera what to do.
RTSP itself carries no media payload. It only negotiates and controls the session that will later carry video and audio over RTP.
Its default port is TCP 554, and it is supported by virtually all IP security cameras, NVRs, and DVRs.
What is RTP?
RTP (Real Time Transport Protocol) is the actual media transport layer defined in RFC 3550.
It carries compressed video such as H.264 or H.265, plus audio formats like G.711 or AAC, in small real-time packets.
RTP uses UDP by default, which keeps latency low but does not guarantee delivery. When firewalls get in the way, it can also run over TCP in interleaved mode — often exposed as rtspt://.
Each RTP packet contains a sequence number for reordering, a timestamp for sync and playback timing, and an SSRC that identifies the stream source.
How RTSP and RTP Work Together
- 1.Client connects to the camera on TCP:554 using RTSP.
- 2.Client sends
DESCRIBEand the camera returns an SDP stream description. - 3.Client sends
SETUPand negotiates RTP ports such as50000/50001. - 4.Client sends
PLAYand the camera starts sending RTP packets to the agreed UDP ports. - 5.RTCP packets flow alongside RTP to exchange timing and quality feedback.
- 6.Client sends
TEARDOWNto end the session.
RTP vs RTSP vs RTMP vs WebRTC
| Protocol | Transport | Latency | Use Case | Firewall Friendly |
|---|---|---|---|---|
| RTSP+RTP | UDP/TCP | Low (100–500ms) | IP cameras, NVR | ❌ (needs port forward) |
RTSP+RTP over TCP (rtspt://) | TCP | Low-medium | Cameras behind NAT | ✅ |
| RTMP | TCP | Low (1–3s) | Live streaming to CDN | ✅ |
| WebRTC | UDP (DTLS) | Very low (<200ms) | Browser video calls | ✅ |
| HLS | HTTP | High (5–30s) | VOD, CDN delivery | ✅ |
RTCP — The Third Member
RTCP runs alongside RTP as the control and reporting companion protocol.
Sender Reports (SR) provide timing and synchronization information from the camera, while Receiver Reports (RR) send packet loss and jitter statistics back from the client.
RTCP usually uses the port immediately after RTP, so if RTP is on 50000, RTCP is on 50001.
SmartRTSP handles RTCP automatically so audio/video sync and stream quality feedback work in the background.
RTP over TCP (rtspt://)
By default, RTP uses UDP. That is ideal for low latency, but some firewalls and routers block the dynamic UDP ports needed for the media stream.
rtspt:// forces both RTSP signaling and RTP media over the same TCP connection.
This makes the stream more reliable through NAT and restrictive firewalls, though latency is usually a little higher than native UDP transport.
SmartRTSP supports rtspt:// natively, which makes it a good fallback when a normal UDP RTSP stream connects but shows no video.
RTP vs RTSP FAQ
What is the difference between RTP and RTSP?
RTSP is the control protocol that manages play, pause, setup, and teardown. RTP is the transport protocol that carries the actual video and audio data packets.
Does RTSP use RTP?
Yes. RTSP negotiates the session, RTP carries the media stream, and RTCP provides feedback about timing, packet loss, and jitter.
What port does RTP use?
RTP normally uses dynamically assigned UDP ports negotiated during RTSP SETUP. RTCP uses the next odd-numbered port.
What is rtspt?
rtspt:// means RTSP with RTP tunneled over TCP instead of UDP, which helps when routers or firewalls block UDP traffic.
Watch RTSP Cameras Without the Protocol Headache
SmartRTSP is a free RTSP viewer for iPhone and Mac. Connect directly to RTSP or rtspt:// camera URLs with hardware-accelerated H.264/H.265 playback and ONVIF auto-discovery.