On Wed, 2009-03-11 at 14:46 +0100, Iñaki Baz Castillo wrote: > 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?
They should repeat the resolution and selection when they refresh the registration returned by sip2 (which is what most clients we've worked with do). If you wanted to force clients to move back as quickly as possible, you could arrange to have sip2 return shorter registrations than sip1 does. There's danger in this, though, since it means sip2 will have higher load than sip1 did (in a large system with short registration times, registration load can be significantly higher than calls). In our system, we make the priorities equal and synchronize the registrations between registrars, so they provide both redundancy and load sharing. It doesn't matter which registrar a client uses. _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
