> > If SRV records not supported, the Contact should > > reflect a single AS > > Did you mean that if SRV records ARE supported?
Hi Attila, Nope. If SRV supported and being used, the SRV records allow the desired order to be clearly indicated. > Isn't the problem that the Contact in the 2xx didn't > contain something that maps to a single device? Depends upon intent. I assume that the person configuring the Contact had reason to supply a Contact able to resolve to more than 1 location. I assume the reason is that the alternative location can occasionally (obviously not always because question posted) be able to handle the in-dialog requests. If the alternative location can never handle the in-dialog requests, I agree that it would be an inappropriate configuration. Cheers, Brett > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Brett Tate > Sent: 20 May 2008 13:42 > To: 孙永光; [email protected] > Subject: Re: [Sip] SIP one DNS domain much IP > > Because of potential load-balancing (as you are observing), > solely using A records within primary/secondary > configurations should be avoided unless additional agreements > or configuration has been made to avoid the situation you are > describing concerning in dialog requests. The additional > agreements override typical rfc3263 behavior by applying > local policy (potentially non compliant) to remain stateful > within dialog. The potential additional configuration (to > avoid the mentioned override) is to have DNS control to avoid > automatic load-balancing/iterating concerning A records so > that the A record query/handling can always result in the > same ordered list. > > RFC 3263 discusses using DNS SRV records to more clearly > indicate prioritization and load-balancing. If SRV records > not supported, the Contact should reflect a single AS unless > the alternative locations can accommodate the situation (or > additional agreements or configuration has been made to avoid > trying the alternative locations first). > _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
