[SR-Users] Using DNS for Service Discovery with Kamailio

[Daniel-Constantin Mierla]

Hello,

if you expect that dispatcher module will list the associated ip
addresses with the hostname after a DNS SRV lookup, then this is not
available.

Dispatcher module will still use the single hostname to set r-uri (or
dst uri) and then TM module does the lookup before sending, inside
t_relay(). Also, irc, the keepalive is sent only to the first ip
resolved for a hostname.

If you want to relay on DNS SRV for loadbalancing, you don't need
dispatcher at all, everything is done transparently for configuration
file by tm and core.

Maybe you can detail a bit more what you want to achieve with dispatcher
on this topic and we can think of alternatives,

Cheers,
Daniel


On 26/01/2017 11:34, Casco, Alessio wrote:
> Thanks for your help,
>
> Unfortunately with kamailio 4.4.4, dispatcher module and your
> suggestions, I still don't see the SRV record picked up (at least
> using the kamcmd  dispatcher.list command).
>
> I didn't try the LCR module yet, I want to be sure first that
> dispatcher is not able to handle SRV first
>
> Thanks
> Alessio
>
> On Wed, Jan 25, 2017 at 8:06 PM, Jeremy Gadd <jeremygadd at gmail.com
> <mailto:jeremygadd at gmail.com>> wrote:
>
>     Holy cow, sorry about that!
>
>     Put the hostname in dispatcher (no port or _sip._udp) and enable
>     these:
>
>     use_dns_cache=on
>     use_dns_failover=on
>     dns_srv_lb=on
>
>     That's how I got it working (using the LCR module).
>
>     On Wed, Jan 25, 2017 at 1:05 PM, Jeremy Gadd <jeremygadd at gmail.com
>     <mailto:jeremygadd at gmail.com>> wrote:
>
>         Put the hostname in dispatcher (no port) and enable these:
>
>
>         On Wed, Jan 25, 2017 at 9:30 AM, Casco, Alessio
>         <alessio.casco at nexmo.com <mailto:alessio.casco at nexmo.com>> wrote:
>
>             Hello Guys!
>
>             I'd like to be able to use SRV records inside dispatcher
>             groups, so I can automatise the discovery of new backends
>             on my network using DNS
>
>             I've tried with the following formats into the
>             dispatcher.list file:
>
>             $group  _sip._udp.sip-voice_backends
>             $group  sip-voice_backends
>
>             and none looks to be working, running the kamailio_ctl
>             dispatcher.list   won't show me the group set with SRV
>             records. ( I also try NAPTR records, with no luck as well.)
>
>             * Does the dispatcher module support SRV or NAPTR records?
>             (maybe my format is not correct) 
>             * If not, do you have any other idea on what I could do to
>             achieve what I'd like to do?
>
>             Thanks
>             Alessio
>
>
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-- 
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
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