>> not necessarily related to the SDP usage. I can't find >> anything, on the RFC >> excerpts you selected, telling that SDP is ok in 180 responses.
Try this: http://www.ietf.org/rfc/rfc3960.txt 1. Unless a 180 (Ringing) response is received, never generate local ringing. 2. If a 180 (Ringing) has been received but there are no incoming media packets, generate local ringing. 3. If a 180 (Ringing) has been received and there are incoming media packets, play them and do not generate local ringing. Note that a 180 (Ringing) response means that the callee is being alerted, and a UAS should send such a response if the callee is being alerted, regardless of the status of the early media session. For me, "180 Ringing" says that the other side is ringing and there will be a ringtone of some kind - maybe you play it or maybe we'll supply it. This is slightly different from 183 Session Progress which seems to imply that there will be some kind of special announcement ("your call is being processed, please wait") or some special prompt tone. Using 180 with SDP is a way to mimic standard POTS system behaviour. For example if I call Italy from the UK, I will always hear an Italian ringback tone. It always seems to be that the ringback should come from a point as near to the ringing entity as possible. Best Regards, Attila Attila Sipos http://www.vegastream.com >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] Behalf >> Of Paulo de >> Arruda Borelli >> Sent: 25 January 2006 08:59 >> To: [EMAIL PROTECTED] >> Cc: [EMAIL PROTECTED]; >> [email protected] >> Subject: Re: [Sip-implementors] 180 Ringing with SDP >> >> >> Hi Amar, >> >> I can't understand why are you talking about reliable >> responses... They are >> not necessarily related to the SDP usage. I can't find >> anything, on the RFC >> excerpts you selected, telling that SDP is ok in 180 responses. >> >> Would you clarify this why you selected these excerpts? >> >> Thank you >> Paulo. >> >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] >> Sent: Wednesday, January 25, 2006 2:46 AM >> To: Paulo de Arruda Borelli >> Cc: [email protected]; >> [EMAIL PROTECTED] >> Subject: Re: [Sip-implementors] 180 Ringing with SDP >> >> Hi, >> >> As per the RFC 3262 any response between 101 to 199 can be >> sent reliably. >> >> From sec 3. >> "A UAS MUST NOT attempt to send a 100 (Trying) response reliably. >> Only provisional responses numbered 101 to 199 may be >> sent reliably. >> If the request did not include either a Supported or >> Require header >> field indicating this feature, the UAS MUST NOT send the >> provisional >> response reliably." >> >> From sec 4. >> "If a provisional response is received for an initial request, and >> that response contains a Require header field containing >> the option >> tag 100rel, the response is to be sent reliably. If the >> response is >> a 100 (Trying) (as opposed to 101 to 199), this option tag MUST be >> ignored, and the procedures below MUST NOT be used." >> >> So there is no harm in sending SDP in 180 ringing for early >> media. You >> should not restrict it only to 183. >> >> >> Rgds, >> Amar >> The greatest enemy of best is "good." If you're willing to >> accept "good" >> you'll never be the "Best." >> >> >> >> >> "Paulo de Arruda >> >> Borelli" >> >> <[EMAIL PROTECTED] >> To >> om.br> >> <[email protected]> >> Sent by: >> cc >> sip-implementors- >> >> [EMAIL PROTECTED] >> Subject >> ia.edu [Sip-implementors] >> 180 Ringing with >> SDP >> >> >> >> 01/25/2006 06:18 >> >> AM >> >> >> >> >> >> >> >> >> >> >> >> Hi, >> >> >> >> Why would an UAC send 180 Ringing with SDP? If it's supposed >> to use early >> media, then 183 Session Progress is more appropriate, right? >> >> >> >> In my understanding, 180 with SDP is contradictory. 180 >> means: "play a >> local >> ringback tone". But the SDP content means: open the media path (in my >> scenario, the original INVITE message did include SDP too). >> >> >> >> So what is the reason for using 180 with SDP in the scenario bellow? >> >> INVITE/SDP from A to B >> >> 180/SDP from B to A >> >> 200/SDP from B to A >> >> >> >> Thank you, >> >> >> >> Paulo A. Borelli >> Gerente de Engenharia / Engineering Manager >> TMais S.A. >> VoIPMais: +55-11-2626-1080, r. 1136 >> Cell: +55-11-9282-5990 >> <BLOCKED::mailto:[EMAIL PROTECTED]> [EMAIL PROTECTED] >> <BLOCKED::http://www.tmais.com.br> www.tmais.com.br >> >> >> >> _______________________________________________ >> Sip-implementors mailing list >> [email protected] >> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> >> >> >> *********************** FSS-Unclassified *********************** >> >> >> _______________________________________________ >> 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
