RFC 3264 says: Once the offerer has sent the offer, it MUST be prepared to receive media for any recvonly streams described by that offer. It MUST be prepared to send and receive media for any sendrecv streams in the offer, and send media for any sendonly streams in the offer (of course, it cannot actually send until the peer provides an answer with the needed address and port information). In the case of RTP, even though it may receive media before the answer arrives, it will not be able to send RTCP receiver reports until the answer arrives.
If the INVITE contained SDP (the offer), the UAC that sent it should be prepared to receive media. Thus, the UAS may begin sending media anytime after accepting the offer. 3264 also says: Once the answerer has sent the answer, it MUST be prepared to receive media for any recvonly streams described by that answer. It MUST be prepared to send and receive media for any sendrecv streams in the answer, and it MAY send media immediately. The answerer MUST be prepared to receive media for recvonly or sendrecv streams using any media formats listed for those streams in the answer, and it MAY send media immediately. Thus, the UAS that received an offer in the INVITE, and sent its answer in the 200-OK (or in a provisional response), it may begin sending media right away. cheers, (-:bob Robert F. Penfield Chief Software Architect Acme Packet, Inc. 71 Third Avenue Burlington, MA 01803 [EMAIL PROTECTED] ----- Original Message ----- From: "Eric Fiorini" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Wednesday, January 25, 2006 3:07 PM Subject: [Sip-implementors] media session > Hi all > > I would like to know as i did not find any clear answer in the concerned > RFCs, if it is acceptable for a UA to start sending media stream after > sending the 200-Ok and before receiving the ACK from the other side of the > call. > > > > Thanks a lot everybody for your help. > > > > Eric Fiorini > > <mailto:[EMAIL PROTECTED]> [EMAIL PROTECTED] > > *+33 4 93 00 88 60 > > > > > _______________________________________________ > 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
