Reliable Internet Stream Transport "RIST" Activity Group
The RIST AG was formed to address the lack of compatibility between devices that provide reliable low-latency transport of high-quality video over public IP networks. This effort has led to many companies and organizations producing products that support RIST. Along with interoperability demos at industry events such as IBC and NAB, RIST is being actively supported by the 150+ members of the RIST Forum (https://www.rist.tv/).
RIST is available as a truly open specification, so any organization can freely download the documents and develop compliant solutions that can be incorporated into products under the included license terms. RIST is also available as open source, with code available in several public repositories, including the LibRIST repository: https://code.videolan.org/rist/librist. RIST has been incorporated into a number of open-source projects, including VLC, FFMPEG, gstreamer, OBS Studio and WireShark.
The following open specifications have been produced:
TR-06-1 (RIST Simple Profile), first released in 2018, defines the basic ARQ (Automatic Repeat Query) technology used to recover lost packets. It has been updated in 2020 to include an optional "RTT Echo" message that streamlines the process of configuring packet buffers.
TR-06-2 (RIST Main Profile), first released in 2020, defines a tunnel using GRE over UDP, where one or more RIST Simple Profile streams can be multiplexed, with optional support for in-band data. RIST Main Profile also includes optional support for encryption and authentication, using both standard DTLS and Pre-Shared Key (PSK). It was revised in 2021 to correct a security issue. It was revised in 2022 to include support for the VSF EtherType. The earlier revisions of TR-06-2 used the experimental EtherTypes for the Reduced Overhead and Keep-Alive packets. VSF has now registered its own EtherType with the IEEE, and thus TR-06-2 has been revised to use this value.
TR-06-3 (RIST Advanced Profile), first released in 2021, provides a protected tunneling mode that can carry any legacy protocol, including RTP-based media signals such as SMPTE ST 2110, ST 2022 and MPEG TS over UDP. In addition, bidirectional protocols based on TCP can be transported securely and reliably in the same packet tunnel while consuming only a single UDP port to simplify firewall configuration. It was revised in 2022 to include a reference to the EAP SHA256-SRP6a Authentication Protocol, which is documented in Annex D of TR-06-2:2022.
TR-06-4 Part 1 (Source Adaptation) released in 2022, defines a protocol for a stream receiver to report current network conditions to a stream sender. Based on this information, the stream sender can dynamically adapt to varying network conditions, either by changing the routing or changing the bit rate.
Work continues within the RIST AG towards developing further RIST specifications that include additional features. All VSF members are welcome to join the RIST AG by contacting the co-chairs.
RIST Activity Group Authorization Form (doc, 63k)