The generic answer is that the re-resolution per rfc3263 should occur for every request (except for CANCEL and ACK-non-2xx). However rfc3261 and rfc3263 provides flexibility so local policy (within and outside of dialog) can override the default behavior.
Since the default behavior can lead to unnecessary delays, it is common to at least re-submit to reachable location first when immediately resubmitting with higher CSeq because of a failure response (like 401, 407, 422, 423, ...). > -----Original Message----- > From: [email protected] [mailto:sip- > [email protected]] On Behalf Of Iñaki Baz > Castillo > Sent: Wednesday, March 11, 2009 9:47 AM > To: sip-implementors > Subject: [Sip-implementors] About SRV when the host with highest priority > becomes reachable > > Hi, imagine a domain "myomain.org" with a SRV _sip._udp register > pointing to two hosts: > > sip1.mydomain.org (priority 1) > sip2.mydomain.org (priority 2) > > Clients MUST contact sip1.mydomain.org since this entry has higher > priority. In case sip1.mydomain.org is down, clients MUST inmediately > use sip2.mydomain.org. > But when should they try to use sip1.mydomain.org? > > Basically I want that clients to come back to the first host and leave > using the second host when sip1.mydomain.org becomes reachable again. > > What should be the client behaviour? > What is the real behaviour of current clients supporting DNS SRV? > > Thanks. > > -- > Iñaki Baz Castillo > <[email protected]> > > _______________________________________________ > 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
