[SR-Users] Kamailio - DMQ dns srv Question

[Charles Chance]

Hi José,

In your config, you need to tell DMQ about a minimum of one other node.
This can be in the form of an IP or FQDN - however, where the FQDN resolves
to a single IP, it does not make sense to perform anything other than an A
lookup, so you should set the parameter to 0 in this case.

The number of nodes in your cluster is irrelevant - once started, DMQ will
contact the one you have told it about and learn about the others
automatically.

Optionally, you can tell DMQ about multiple nodes upfront (to account for
instances where the first one may be down or unreachable), by giving it an
FQDN which resolves to multiple IP addresses - in which case you'll need to
set the multi_notify parameter to 1.

Does that help?

Cheers,
Charles


On 22 September 2016 at 13:36, José Seabra <joseseabra4 at gmail.com> wrote:

> Hi Charles
> I have modparam("dmq", "multi_notify", 1) because my A record resolves
> more than one Kamailio addresses, and if i understood well the
> documentation says that we need set it to a value different of 0 to resolve
> all ip addresses associated to the Name configured on DMQ.
> I'm using DMQ with 4 kamailio instances, so i think that i need have it
> set to a value different than 0, or i'm wrong?.
>
> Documentation says:
>
> Enables the ability to resolve multiple IPv4/IPv6 addresses for a single
> notification address.
>
> A value of zero resolves to the first IP address found. A non-zero value
> resolves to all IP addresses associated with the host. This includes
> addresses from DNS SRV records, A and AAAA records.
>
> *Default value is “0”.*
>
> Thank you
> Cheers
> José
>
>
>
> 2016-09-22 13:28 GMT+01:00 Charles Chance <charles.chance at sipcentric.com>:
>
>> Hey,
>>
>> On 22 September 2016 at 12:18, José Seabra <joseseabra4 at gmail.com> wrote:
>>
>>> Hello Daniel and Charles,
>>> Thank you for your feedback.
>>> Another doubt is when we use a FQDN that only resolves as A record,
>>> would be better DMQ send only a A query or is there any reason for always
>>> try SRV?
>>>
>>>
>> As far as I recall (it's been a while since I did anything with this),
>> the default behaviour is to query A record only. There is a mod_param to
>> enable multi-record/SRV lookup:
>>
>> modparam("dmq", "multi_notify", 1)
>>
>> But the default is off.
>>
>> Is this not the behaviour you are seeing?
>>
>> Cheers,
>> Charles
>>
>>
>>
>>
>>> Thank you for your great job.
>>>
>>> BR
>>> José Seabra
>>>
>>> 2016-09-22 8:33 GMT+01:00 Charles Chance <charles.chance at sipcentric.com>
>>> :
>>>
>>>> Hello,
>>>>
>>>> I can take a look today.
>>>>
>>>> Cheers,
>>>> Charles
>>>>
>>>> On 22 Sep 2016 06:20, "Daniel-Constantin Mierla" <miconda at gmail.com>
>>>> wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I guess that the one who did the implementation of the srv query for
>>>>> dmq hasn't "allocated" any service name. I haven't looked at the sources,
>>>>> but I guess it should be a small patch to compose the srv dns string to be
>>>>> queried -- maybe that part can be made a mod param so each can choose its
>>>>> preferred service.
>>>>>
>>>>> Cheers,
>>>>> Daniel
>>>>>
>>>>> On 21/09/16 19:28, José Seabra wrote:
>>>>>
>>>>> Hello,
>>>>> I have a doubt related with DMQ dns behavior, I noticed that when
>>>>> kamailio starts, it tries to resolve DMQ name configured on parameter
>>>>> notification_address as the following sequence:
>>>>>
>>>>>    1. SRV
>>>>>    2. A
>>>>>    3. AAAA
>>>>>
>>>>>
>>>>> Isn't supposed kamailio  try first resolve the  NAPTR DMQ name, and
>>>>> then SRV?
>>>>> I'm asking this because kamailio is trying resolve the SRV record
>>>>> without any transport protocol specified on query, as my dns server only
>>>>> accepts queries on the format "_Service._Proto.Name" the SRV will never be
>>>>> resolved.
>>>>>
>>>>> Thank you.
>>>>> BR
>>>>> --
>>>>> José Seabra
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing listsr-users at lists.sip-router.orghttp://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>>>
>>>>>
>>>>> --
>>>>> Daniel-Constantin Mierlahttp://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>>>>> Kamailio Advanced Training, Berlin, Oct 24-26, 2016 - http://www.asipto.com
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>>>>> sr-users at lists.sip-router.org
>>>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>>>
>>>>>
>>>> Sipcentric Ltd. Company registered in England & Wales no. 7365592. Registered
>>>> office: Faraday Wharf, Innovation Birmingham Campus, Holt Street,
>>>> Birmingham Science Park, Birmingham B7 4BB.
>>>>
>>>> _______________________________________________
>>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>>>> sr-users at lists.sip-router.org
>>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>>
>>>>
>>>
>>>
>>> --
>>> Cumprimentos
>>> José Seabra
>>>
>>> _______________________________________________
>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>>> sr-users at lists.sip-router.org
>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>
>>>
>>
>>
>>
>> Sipcentric Ltd. Company registered in England & Wales no. 7365592. Registered
>> office: Faraday Wharf, Innovation Birmingham Campus, Holt Street,
>> Birmingham Science Park, Birmingham B7 4BB.
>>
>> _______________________________________________
>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>> sr-users at lists.sip-router.org
>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>
>>
>
>
> --
> Cumprimentos
> José Seabra
>
> _______________________________________________
> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> sr-users at lists.sip-router.org
> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>
>

-- 
Sipcentric Ltd. Company registered in England & Wales no. 7365592. Registered 
office: Faraday Wharf, Innovation Birmingham Campus, Holt Street, 
Birmingham Science Park, Birmingham B7 4BB.
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