Hi, if you want failover support, you need to have a couple of core dns parameters enabled: https://www.kamailio.org/wiki/cookbooks/5.2.x/core#use_dns_cache and https://www.kamailio.org/wiki/cookbooks/5.2.x/core#use_dns_failover The latter defaults to off. Cheers, Federico On Thu, Jun 6, 2019 at 10:10 PM JR Richardson <jmr.richardson(a)gmail.com> wrote: > Hey All, > > I'm in the lab testing kamailio 5.2 with DNS SRV records. The scenario > is simple, using dispatcher with hard coded IP URIs > [sip:10.10.10.10:5060] and also a DNS name URI [sip:sip.domain.com]. > There are 2 SRV servers. > > The DNS SRV records are setup and resolving OK, during startup, > kamailio list the DNS name in the dispatcher list. > > During a call scenario, when the dispatcher selects the DNS name URI > for the next destination, the TM module takes over, resolves the > _sip._udp.sip.domain.com for both SRV records OK and sends the call to > the first SRV server in the list. But if I take the first SRV server > offline, make another call, the TM module does not route to the second > SRV server until the DNS record timeout is reached, in my lab was set > for 300 seconds. I decreased the DNS SRV record TTL down to 5 seconds > with same results above, but 5 seconds lapse when TM routes call to > next SRV server. > > I think this is working as expected but not sure if this is by design > so my question is, should the TM module route to another SRV server in > the list in the event of a no response timeout or send the transaction > back to the dispatcher to select another target? > > Should I play around with the TM Module parameter > "max_noninv_lifetime" to get quicker results or it is better to have > DNS SRV record TTL set really low? > > Thanks. > > JR