Hi, I think the first preference must be a=sendonly followed by c=0.0.0.0 which is just the backward compatibility. This will also ensure the cases where in the given SDP, some m lines are on hold while some are not.
Regards, Somesh S Shanbhag M G L Bangalore -----Original Message----- From: [EMAIL PROTECTED] on behalf of Subbu Rajendran Sent: Fri 10/24/2008 3:40 PM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] SIP media change - Is the precedence forc=0.0.0.0 or a= attribute? Hi, SIP RFC 2543 uses c=0.0.0.0 method to put a call on hold. RFC 3264 has introduced a=sendonly/recvonly/inactive/sendrecv attributes that can be used put media to one way, hold and 2-way. However what should be the precedence to be followed? Consider the case below A Re-INVITE with SDP v=0 o=user1 53655765 2353687637 IN IP4 192.168.1.100 s=- c=IN IP4 0.0.0.0 t=0 0 m=audio 6001 RTP/AVP 0 a=rtpmap:0 PCMU/8000 a=recvonly How should the SIP endpoint receiving this Re-INVITE interpret the SDP, w.r.t the flow of media. Which method should be given preference. Any help in this context is very much appreciated. Thanks & Regards, Subbu _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors EMAIL DISCLAIMER : This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. Any unauthorised distribution or copying is strictly prohibited. If you receive this transmission in error, please notify the sender by reply email and then destroy the message. Opinions, conclusions and other information in this message that do not relate to official business of Mascon shall be understood to be neither given nor endorsed by Mascon. Any information contained in this email, when addressed to Mascon clients is subject to the terms and conditions in governing client contract. Whilst Mascon takes steps to prevent the transmission of viruses via e-mail, we can not guarantee that any email or attachment is free from computer viruses and you are strongly advised to undertake your own anti-virus precautions. Mascon grants no warranties regarding performance, use or quality of any e-mail or attachment and undertakes no liability for loss or damage, howsoever caused. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
