[SR-Users] Kamailio Active / Active HA.

[Carsten Bock]

Hi Ben,

that's absolutely for sure! It took us ~2 years to get the DNS-SRV
implementation of major DSL-Modem-Manufacturer right ;-)
Nevertheless, it's the way to go for redundancy. And since Mobicents
is open-source, we can probably simply provide a patch to fix it :-)

Kind regards,
Carsten

2014-12-29 12:13 GMT+01:00 Ben Langfeld <ben at langfeld.co.uk>:
> On 27 December 2014 at 23:44, Carsten Bock <carsten at ng-voice.com> wrote:
>>
>> Hi Mahmoud,
>>
>> Thy typical way, to build a Active/Active setup is by using DNS-SRV
>> records. The two servers get different IPs and you announce both IPs
>> using DNS to the devices. Most common User-Agents support this
>> nowadays, so that's kind of easy. It is specified in RFC3263:
>> "Locating SIP-Servers" (http://tools.ietf.org/html/rfc3263).
>>
>> However, when using DNS-SRV records, dialogs and transactions are
>> still associated with a single server, even though the User-Agent has
>> an Alternative, in case one server fails. If you want to increase the
>> HA for this, you can advertise the Domain name instead of an IP
>> (causes more DNS-Lookups).
>
>
> Just a word of caution here, there are several SIP stacks which don't handle
> SRV lookups correctly. I don't mean to discourage you from this, but just to
> be aware of it. For example, Mobicents only understands SRV record sets
> which return domain names. If you return IPs, Mobicents will go ahead and
> look them up as A records and fail.
>
>>
>> You can share the dialog state etween two nodes by using the dialog
>> module in db-only mode (db_mode = 1, see
>> http://kamailio.org/docs/modules/devel/modules/dialog.html#idp15368320).
>> You cannot share transactions between two nodes, only dialogs.
>>
>> In addition, you can work with virtual IPs with Heartbeat/Pacemaker.
>>
>> At a big operator, we've used a combination of the two: Active/Passive
>> for one site and DNS-SRV to distribute it among different sites.
>>
>> Kind regards,
>> Carsten
>>
>> 2014-12-26 19:07 GMT+01:00 Mahmoud Ramadan Ali
>> <cisco.and.more.blog at gmail.com>:
>> > Hi Dears,
>> > I have successfully configured Kamailio HA using Heartbeat and Pacemaker
>> > so
>> > if one of the two servers should go down the other server will own the
>> > virtual IP address and take over.
>> > But i have two questions:
>> >
>> > 1.This model is considered to be Active / Passive redundancy so one
>> > server
>> > will process the SIP signaling until it goes down and i'm wondering is
>> > there
>> > is any way two achieve Active / Active redundancy and if so how the
>> > signaling will be handled on the servers so they can be aware of the
>> > transactions and dialogs traversing the servers ? does the signalling
>> > will
>> > be replicated or synchronized between the servers or what ?!
>> >
>> > 2.What about the servers DB and how they should be designed in a cluster
>> > mode ? i want to replicate all the DBs of the server to get consistent
>> > user
>> > registration using the subscriber table for example.
>> >
>> > Thanks in advance and Best regards.
>> >
>> > _______________________________________________
>> > 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
>> >
>>
>>
>>
>> --
>> Carsten Bock
>> CEO (Geschäftsführer)
>>
>> ng-voice GmbH
>> Schomburgstr. 80
>> D-22767 Hamburg / Germany
>>
>> http://www.ng-voice.com
>> mailto:carsten at ng-voice.com
>>
>> Office +49 40 5247593-0
>> Fax +49 40 5247593-99
>>
>> Sitz der Gesellschaft: Hamburg
>> Registergericht: Amtsgericht Hamburg, HRB 120189
>> Geschäftsführer: Carsten Bock
>> Ust-ID: DE279344284
>>
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>>
>> _______________________________________________
>> 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
>
>
>
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>



-- 
Carsten Bock
CEO (Geschäftsführer)

ng-voice GmbH
Schomburgstr. 80
D-22767 Hamburg / Germany

http://www.ng-voice.com
mailto:carsten at ng-voice.com

Office +49 40 5247593-0
Fax +49 40 5247593-99

Sitz der Gesellschaft: Hamburg
Registergericht: Amtsgericht Hamburg, HRB 120189
Geschäftsführer: Carsten Bock
Ust-ID: DE279344284

Hier finden Sie unsere handelsrechtlichen Pflichtangaben:
http://www.ng-voice.com/imprint/