Hi Tim, Although the SDP RFC allows a FQDN in the c-line, for SIP I believe that only IP addresses should be used. I'm not sure if that is called out in bis or some other draft.
If some of the media streams are acceptable, you could just disable the unacceptable ones by setting the port number to 0 in accordance with http://www.ietf.org/internet-drafts/draft-rosenberg-mmusic-sdp-offer-answer- 00.txt Otherwise you should reject the request with a 488 (Unacceptable Here) response. If there are no acceptable streams, a 488 should be returned. If the offer is in a 200-OK, you need to send the ACK. But then you would need to re-INVITE or send a BYE immediately. If you're going to send BYE, you probably want to set all the port numbers to 0 in the answer SDP in the ACK so that the far end does not start sending media. cheers, (-:bob Robert F. Penfield Chief Software Architect Acme Packet, Inc. 130 New Boston Street Woburn, MA 01801 [EMAIL PROTECTED] ----- Original Message ----- From: "Tim Johnson" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, November 08, 2001 9:45 PM Subject: [Sip-implementors] SDP with unresolved connection address > I have a question about what, if any, SIP behaviour there should be > if a UA receives SDP with a connection address expressed as a > domain name and which cannot be resolved. In this case at least one, > and possibly all, media streams cannot be sent. This is also similar > to an ARP failure on a LAN but probably much more likely to occur. > There is also a similarity to receiving an ICMP unreachable > indication for a media stream in progress. In all cases the media > cannot be sent yet the signalling channel, especially in the case of > 3PCC, may be unaffected. > > If the SDP was in an INVITE, the response could indicate a DNS > resolution failure (although no response codes are defined which > cover this specific case). But the SDP could also be in either a 2xx > response or in an ACK. In these cases, a re-INVITE could be sent > following the completion of the INVITE transaction which > contained the unresolved name. Alternatively, a BYE could be sent > to terminate the session. Finally, the session could be unaffected and > corrective actions left to the user which notices a lack of media. > > Only the BYE seems deterministic since a response to a re-INVITE > is likely to contain the same SDP as caused the resolution failure. > However it would appear to be too drastic if there were other media > streams in the session which did resolve (i.e. the c= which did not > resolve was within one of several media descriptions and not at the > session level). What is the accepted solution here? > > Thanks, > Tim > > _______________________________________________ > Sip-implementors mailing list > [EMAIL PROTECTED] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
