AudioCodes E-SBC - Page 451

CHAPTER19 Coders and Profiles
Mediant 1000 Gateway & E-SBC | User's Manual
Parameter Description
The parameter supports indication of RTCP-based
feedback, according to RFC 5124, during RTP profile
negotiation between two communicating SIP entities. RFC
5124 defines an RTP profile (S)AVPF for (secure) real-time
communications to provide timely feedback from the
receivers to a sender. For more information on RFC 5124,
see http://tools.ietf.org/html/rfc5124.
Some SIP entities may require RTP secure-profile
feedback negotiation (AVPF/SAVPF) in the SDP
offer/answer exchange, while other SIP entities may not
support it. The device indicates whether or not feedback is
supported on behalf of the SIP entity. It does this by adding
an "F" or removing the "F" from the SDP media line ('m=')
for AVP and SAVP. For example, the following shows
"AVP" appended with an "F", indicating that the SIP entity
is capable of receiving feedback
m=audio 49170 RTP/SAVPF 0 96
■ [0] Feedback Off = (Default) The device does not send
the feedback flag ("F") in SDP offers/answers that are
sent to the SIP entity. If the SDP 'm=' attribute of an
incoming message that is destined to the SIP entity
includes the feedback flag, the device removes it
before sending the message to the SIP entity.
■ [1] Feedback On = The device includes the feedback
flag ("F") in the SDP offer sent to the SIP entity. The
device includes the feedback flag in the SDP answer
sent to the SIP entity only if it was present in the SDP
offer received from the other SIP entity.
■ [2] As Is = The device does not involve itself in the
feedback, but simply forwards any feedback indication
as is.
Note:
■ As RTCP-based feedback has been defined by the
WebRTC standard as mandatory, the support is
important for deployments implementing WebRTC. For
more information on WebRTC, see WebRTC.
Quality of Service
'RTP IP DiffServ'
rtp-ip-diffserv
[IpProfile_IPDiffServ]
Defines the DiffServ value for Premium Media class of
service (CoS) content.
The valid range is 0 to 63. The default is 46.
Note: The corresponding global parameter is
PremiumServiceClassMediaDiffServ.
'Signaling DiffServ'
signaling-diffserv
[IpProfile_SigIPDiffServ]
Defines the DiffServ value for Premium Control CoS
content (Call Control applications).
The valid range is 0 to 63. The default is 40.
Note: The corresponding global parameter is
PremiumServiceClassControlDiffServ.
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