AudioCodes Mediant 500 MSBR, Руководство пользователя

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Version 7.2 417 Mediant 500 MSBR
User's Manual 23. Coders and Profiles
Parameter Description
[IpProfile_SBCSDPHandleRTCP
Attribute] that port is not the next higher port number following the RTP
port specified in the media line ('m=').
The parameter is useful for SIP entities that either require the
attribute or do not support the attribute. For example, Google
Chrome and Web RTC do not accept calls without the RTCP
attribute in the SDP. In Web RTC, Chrome (SDES) generates
the SDP with 'a=rtcp', for example:
m=audio 49170 RTP/AVP 0
a=rtcp:53020 IN IP6
2001:2345:6789:ABCD:EF01:2345:6789:ABCD

[0] Don't Care = (Default) The device forwards the SDP as is
without interfering in the RTCP attribute (regardless if present
or not).

[1] Add = The device adds the 'a=rtcp' attribute to the
outgoing SDP offer sent to the SIP entity if the attribute was
not present in the original incoming SDP offer.

[2] Remove = The device removes the 'a=rtcp' attribute, if
present in the incoming SDP offer received from the other
SIP entity, before sending the outgoing SDP offer to the SIP
entity.
Note: As the RTCP attribute has been defined by the WebRTC
standard as mandatory, the support is important for deployments
implementing WebRTC. For more information on WebRTC, see
WebRTC.
RTCP Mux
sbc-rtcp-mux
[IPProfile_SBCRTCPMux]
Enables interworking of multiplexing of RTP and RTCP onto a
single local port, between SIP entities. The parameter enables
multiplexing of RTP and RTCP traffic onto a single local port, for
the SIP entity associated with the IP Profile.
Multiplexing of RTP data packets and RTCP packets onto a
single local UDP port is done for each RTP session (according to
RFC 5761). If multiplexing is not enabled, the device uses
different (but adjacent) ports for RTP and RTCP packets.
With the increased use of NAT and firewalls, maintaining multiple
NAT bindings can be costly and also complicate firewall
administration since multiple ports must be opened to allow RTP
traffic. To reduce these costs and session setup times, support
for multiplexing RTP data packets and RTCP packets onto a
single port is advantageous.
For multiplexing, the initial SDP offer must include the "a=rtcp-
mux" attribute to request multiplexing of RTP and RTCP onto a
single port. If the SDP answer wishes to multiplex RTP and
RTCP, it must also include the "a=rtcp-mux" attribute. If the
answer does not include the attribute, the offerer must not
multiplex RTP and RTCP packets. If both ICE and multiplexed
RTP-RTCP are used, the initial SDP offer must also include the
"a=candidate:" attribute for both RTP and RTCP along with the
"a=rtcp:" attribute, indicating a fallback port for RTCP in case the
answerer does not support RTP and RTCP multiplexing.

[0] Not Supported = (Default) RTP and RTCP packets use
different ports.

[1] Supported = Device multiplexes RTP and RTCP packets
onto a single port.