Arbitrary RTP Header Extensions

[aboba]

Does RtpTransport allow an application to send arbitrary octets in RTP header extensions?

What restrictions are placed on the IDs/content of RTP header extensions?

• IDs that can be used
• Control over encryption (RFC 6904 or RFC 9335)
• Content (for congestion-control related extensions)
• Content (for other extensions)

[dontcallmedom-bot]

This issue was mentioned in WEBRTCWG-2023-12-05 (Page 58)

[youennf]

For send side, there would be a need for a registration API that would modify the SDP and map the header extension URI to the extension ID.

For read side, this API would be nice but is not mandatory if the extension ID is exposed directly.
Note also that reading header extension is easier since there is no issue related to bad data or conflicting IDs.