[ Moving to SIP Implementors ] > If after sending an Invite a Record-Route header is received in > a provisional response and then a final response is received > without a Record-Route header what are the ramifications of > sending the ACK without a route header? If the (2xx) response contained no Record-Route then the ACK should be sent directly to the address in the Contact header (Contact in 2xx is mandatory in bis). Record-Route in provisional is meaningless, unless reliable responses are being used (as I recall). > If the ACK is sent with same data as the Invite will the > ACK not travel the same path as teh invite? You can't guarantee it, since there may have been some random or otherwise temporal basis to the routing involved. > What happens in the following scenario? > > A final response is received out of the blue (no > active transaction). It was possible that the > record-route was received in a previous response. > However it this example the transaction timed-out and > was deleted before the final response was received. > After getting the final response an ACK is built based > on the data in the final response and sent. If the > final response did not contain a record-route the > ACK would not have a Route header. I would consider this a non-problem. How is a client supposed to know where to send the ACK if it can't even recall the INVITE? In general, I would think the best idea is just to silently drop unknown responses; doing anything more helpful is -- I would say -- an unnecessary amount of effort, since the only useful thing it will do is stop response retx. HTH, - Jo. _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
