Prior to rfc3311 (UPDATE), INFO without body was commonly used to check dialog state as alternative to using re-INVITE. Now that rfc3311 is available, it is more commonly used.
If Twinkle supports rfc2976, it must return 200 instead of 415 when INFO contains no body. RFC 2976 section 2.2: "A 200 OK response MUST be sent by a UAS for an INFO request with no message body if the INFO request was successfully received for an existing call." "A 481 Call Leg/Transaction Does Not Exist message MUST be sent by a UAS if the INFO request does not match any existing call leg." > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of Iñaki Baz Castillo > Sent: Wednesday, May 28, 2008 9:32 AM > To: [email protected] > Subject: [Sip-implementors] Nortel CS2K sends an in-dialog > INFO to monitorize call ¿?¿?¿ > > Hi, Nortel CS2K sends an in-dialog INFO to monitorize long > duration calls. The INFO is completely incorrect: > > --------- > INFO sip:[EMAIL PROTECTED]:1030;transport=udp SIP/2.0 > From: <sip:[EMAIL PROTECTED]>;tag=5242163708552008528143418 > To: "IBC"<sip:[EMAIL PROTECTED]>;tag=khanw > Call-ID: [EMAIL PROTECTED] > CSeq: 1 INFO > User-agent: CS2000_NGSS/9.0 > Max-Forwards: 70 > Supported: 100rel > Allow: > ACK,BYE,CANCEL,INVITE,OPTIONS,INFO,SUBSCRIBE,REFER,NOTIFY,PRACK,UPDATE > Via: SIP/2.0/UDP > 66.24.0.144:5060;maddr=66.24.0.144;branch=z9hG4bK-5e1ce8-6fa0e cb5-4eb6d9b1 > Contact: <sip:66.24.0.144:5060;transport=UDP> > Route: <sip:88.99.3.10;lr;ftag=khanw> > Content-Length: 0 > --------- > > Of course, some *good* clients (as Twinkle) replies with "415 > Unsupported Media Type" and then Nortel terminates the audio > and after 20 secods sends the BYE. > So in my proxy I have had to set a rule that replies with > "200 OK" directly to any INFO from the Nortel. > > > I'm 100% sure that this INFO use is completely anti-RFC, but > I would apreciate if someone can tell me how common is using it. > > Thanks a lot. > > > > -- > Iñaki Baz Castillo > [EMAIL PROTECTED] > > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
