Updates to RFC 5761
Ericsson
Hirsalantie 11
Jorvas
02420
Finland
christer.holmberg@ericsson.com
RAI
This document updates RFC 5761 by clarifying the SDP offer/answer negotiation of
RTP and RTCP multiplexing. It makes it clear that an answerer can only include
an "a=rtcp-mux" attribute in an SDP answer if the associated SDP offer contained
the attribute.
RFC 5761
specifies how to multiplex RTP data packets and RTP Control Protocol
(RTCP) packets on a single UDP port, and how to negotiate usage of
such multiplexing using the SDP offer/answer mechanism
, using an
"a=rtcp-mux" attribute. However, the text is unclear on whether an
answerer is allowed to include the attribute in an answer
even if the associated offer did not contain an attribute.
This document updates RFC 5761
by clarifying that an answerer can only include an "a=rtcp-mux"
attribute in an answer if the associated offer contained the attribute.
It also clarifies that the negotiation of RTP and RTCP multiplexing is
for usage in both directions.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in .
This section updates section 5.1.1 of RFC 5761
by clarifying that an answerer can only include an "a=rtcp-mux"
attribute in an answer if the associated offer contained the attribute,
and by clarifying that the negotiation of RTP and RTCP multiplexing is
for usage in both directions.
The security considerations for RTP and RTCP multiplexing are
described in RFC 5761. This specification does not impact those
security considerations.
This specifcation makes no requests from IANA.
Thanks to Colin Perkins, Magnus Westerlund, Paul Kyzivat, Roni Even for
providing comments on the document. Thomas Belling provided useful input
in the discussions that took place in 3GPP and resulated in the submission
of the document.
[RFC EDITOR NOTE: Please remove this section when publishing]
Change from -01
pre-RFC5378 disclaimer added.
Change from -00
Editorial changes based on WGLC comments from Roni Even.