Hi all, I hope this is the right forum for my inquiry. what is the intent of the T38maxBitRate capability in the body of an SIP/SDP session (when using UDPTL)? I assumed that this parameter would be negotiated the same way a codec would be in a regular SIP voice call. However, I have found this not to be the case during integration testing and I have read conflicting statements in the T.38 standard. Specifically,
Section D.2.3 of the T.38 standards says: "RFC 2327 Session Description Protocol (SDP) provides mechanisms for describing sessions for SIP. There are several T.38 specific parameters that may be negotiated when establishing a T.38 media stream. For historic reasons, this is done differently for the UDPTL/TCP transport and the RTP transport." And then section D.2.3.1 (UDPTL) goes on to list the T.38 specific parameters, one of which is T38maxBitRate. Then in Section D.2.7 of the T.38 standard I find: "T38maxBitRate refers to the maximum fax data rate that is supported by an endpoint. When TCP is used for T.38 facsimile transmission, T38maxBitRate does not apply. When UDP is used for T.38 facsimile transmission, T38maxBitRate should be specified to aid in bandwidth allocation." So, which one is it? Is the parameter to be negotiated or only use as a reference point for bandwidth allocation? Thanks, Fernando Lombardo McLeodUSA NOTICE: This electronic mail transmission may contain confidential information and is intended only for the person(s) named. Any use, copying or disclosure by any other person is strictly prohibited. If you have received this transmission in error, please notify the sender via e-mail. _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
