Pierre-Luc Bacon schrieb: > The way I interpret this excerpt, I would rather say "Fortunately yes" > because it means it has to be fixed in PJSIP and not be hacked around on > the application side. > >>From RFC 3261 [5], just to make sure that I have the right understanding > of "transaction" : > > "A transaction is a request sent by a > client transaction (using the transport layer) to a server > transaction, along with all responses to that request sent from the > server transaction back to the client. The transaction layer handles > application-layer retransmissions, matching of responses to requests, > and application-layer timeouts." > > With "The transaction layer handles application-layer retransmissions, > matching of responses to requests", then the REGISTER sent after a 407 > challenge is part of the transaction and therefore, the DNS procedures > defined in RFC 3263 [4] must be applied. No. Every REGISTER is a separate transaction - except retransmissions which can be identified by being completely identical in contrast to the new REGISTER request which is different (at least CSeq or call-id or from-tag or Via-branch are different). Actually, the branch-parameter in the via header is used for transaction matching. Thus, a new branch parameter indicates a new transaction. Thus, pjsip/pjsua-lib behaves standard conform, but is not useable in practical. regards klaus > > On Fri, 2009-07-17 at 16:29 +0200, Klaus Darilion wrote: >> Pierre-Luc Bacon schrieb: >>> Now, does the RFC say to do so ? >> Unfortunately yes. >> >> RFC 3263: >> >>> The procedures here MUST be done exactly once per transaction, where >>> transaction is as defined in [1]. That is, once a SIP server has >>> successfully been contacted (success is defined below), all >>> retransmissions of the SIP request and the ACK for non-2xx SIP >>> responses to INVITE MUST be sent to the same host. Furthermore, a >>> CANCEL for a particular SIP request MUST be sent to the same SIP >>> server that the SIP request was delivered to. >> From a practical point of view this is bad (as you experienced), >> because if there is a dialog stateful element (e.g. SBC, IP-PBX), the >> in-dialog requests will be rejected and nonces wont be accepted. >> >> Thus, IMO the client should send all messages which belong together >> (re-registrations, in-dialog requests) to the same IP address (usually >> the one which was resolved during initial registration). Only if there >> is a problem, the domain should be resolved again and a new IP should be >> choosen. >> >> regards >> klaus >> >
