RIST
Reliable Internet Stream Transport uses RTP-based retransmission for media over lossy networks. VSF TR-06 Simple, Main and Advanced profiles have different tunnelling, security and multiplexing capabilities.
Scope: Select RIST profile and deployed transport mode
protocol · Catalog reviewed 2026-09-27
VSF TR-06-1:2020; TR-06-2:2024; TR-06-3:2024
Infrastructure Requirements
- Compatible profile and endpoint settings, configured addresses/ports, return path for recovery requests, and a recovery buffer sized for round-trip time and expected loss.
Network & Physical Requirements
| Port / allocation | Transport | Connection / signal flow | Feature and requirement | Evidence |
|---|---|---|---|---|
| Configured | UDP | RIST sender → RIST receiver | Optional · Simple Profile RTP media to configured even UDP port P RIST Simple Profile 2020 Set the destination explicitly. P is an even number from 2 to 65534; this permitted set is not a firewall range to open. | Source checked 2026-09-27 5.1.1–5.1.2 |
| Configured | UDP | RIST sender → RIST receiver | Optional · Simple Profile Sender RTCP to UDP port P+1 RIST Simple Profile 2020 Use the port immediately above the configured RTP destination. For multicast, RTP and RTCP use the same group. | Source checked 2026-09-27 5.1.1–5.1.2 |
| Negotiated | UDP | RIST receiver → RIST sender | Optional · Simple Profile Receiver feedback and retransmission requests RIST Simple Profile 2020 Unicast feedback returns to the observed sender RTCP source address/port. Multicast feedback uses the media group and P+1. Account for NAT state. | Source checked 2026-09-27 5.1.1–5.1.2 |
| Configured | UDP | Configured tunnel client → Configured tunnel server | Optional · Main Profile tunnel GRE-over-UDP tunnel traffic RIST Main Profile 2024 The server listens on a user-configured UDP port; replies return to the client. Either media direction can use the tunnel. Ports 4754/4755 are not mandatory RIST ports. | Source checked 2026-09-27 5.2 GRE tunnel transport |
| Configured | UDP | RIST Advanced peer → Configured peer tunnel listener | Optional · Advanced Profile tunnel Protected data and control over the configured UDP tunnel RIST Advanced Profile 2024 Match connection setup, multiplexing and optional DTLS. If FEC is sent outside the tunnel, separately schedule its configured row/column ports. | Source checked 2026-09-27 5.2.1; 5.3.5; 6–7 |
Gotchas & IT Notes
- ⚠Select the deployed profile. Simple Profile uses separate RTP and RTCP; Main and Advanced can carry traffic inside tunnels.
- ⚠Match security and authentication settings. Simple Profile alone does not encrypt media.
- ⚠Allow capacity for retransmissions and confirm NAT/firewall behavior in both directions.