On 03/10/2011 03:30 PM, Saúl Ibarra Corretgé wrote: > Hi, > > While testing a SIP client I work on I noticed that there was some > interoperability issue with a certain PBX. This PBX will issue a > re-INVITE to both call legs once the call is established so that they > direct the RTP directly, without traversing the server. While doing > this, the origin SDP attribute is also modified in the following way: > > Initial INVITE: > > o=root 1697225829 1697225829 IN IP4 192.168.1.79 > > re-INVITE > > o=root 1697225829 1697225830 IN IP4 192.168.1.47 > > RFC3264, sec 8 says the following: > > "When issuing an offer that modifies the session, > the "o=" line of the new SDP MUST be identical to that in the > previous SDP, except that the version in the origin field MUST > increment by one from the previous SDP." > > By reading that I understand that this PBX is doing it wrong because > the host is also changed. However, I tested this same thing with a > Snom phone and it did accept the re-INVITE.
I believe you are correct, the host address should not be changed in the 'o' line... it's not really used for anything except identifying the session anyway, there's no value in changing it. If the PBX in question is the one I think it is, this behavior does not surprise me :-) -- Kevin P. Fleming Digium, Inc. | Director of Software Technologies Jabber: [email protected] | SIP: [email protected] | Skype: kpfleming 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at www.digium.com & www.asterisk.org _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
