> The problem is that on UAC we start the sending the RTP media > as soon as we > send out ACK for the INVITE, but on UAS we open the RTP ports > only when the > ACK is received. So because of this first few packets may be > droped on UAS > side if the RTP packet reach UAS before the ACK(which is > possible on the UDP > transport)
Your UAS must be prepared to receive media as soon as it sends a response with SDP (probably the 200, although other call flows are possible). RFC3264 Section 5.1 (last paragraph): 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) There is a similar clause in section 6.1, putting the same burden on answerers. Regards, Michael Procter _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
