Medias Mediatrix 1204, Reference Manual

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Chapter 18 - SIP Protocol Features Offer/Answer Model
236 Mediatrix 1204
Offer/Answer Model
You can define whether the Mediatrix 1204 requires strict adherence to RFC 3264 from the peer when
negotiating capabilities for the establishment of a media session.
X
To define how to process the Offer/Answer model:
1. In the sipExperimentalMIB , set the sipEnforceOfferAnswerModel variable to the proper value.
The following values are available:
enable Support for the above T.38 parameters is advertised in conformance with ITU-T
Recommendation T.38, section D.2.3. The presence of the parameter in the SDP
indicates support for it (without the need for an associated value), while its absence
means that it is not supported.
Table 151: T.38 Negotiation Syntax Usage (Continued)
Parameter Description
Standards Supported • RFC 3264 – An Offer/Answer Model with the Session
Description Protocol (SDP)
Table 152: Offer/Answer Model Parameters
Parameter Description
disable The peer can freely:
• Send back a brand new list of codecs or add new ones to the offered
list.
• Add media lines AFTER the ones found in the offer.
As long as at least one codec sent back is supported by the Mediatrix 1204,
the call is allowed to go on. Any media lines added by the peer is simply
ignored.
enable The following guidelines from the Offer-Answer Model must be strictly
followed. An answer must:
• Include at least one codec from the list that the Mediatrix 1204 sent
in the offer.
• Avoid adding extra codecs that were not present in the offer.
• Contain the same number of media lines that the unit put in its offer.
Otherwise, the answer is rejected and the unit ends the call. This is the default
value.