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(a)langfeld.co.uk>uk>:
On 27 December 2014 at 23:44, Carsten Bock
<carsten(a)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(a)gmail.com>om>:
> > 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(a)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@ng-voice.com
>
> Office +49 40 5247593-0
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>
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--
Carsten Bock
CEO (Geschäftsführer)
ng-voice GmbH
Schomburgstr. 80
D-22767 Hamburg / Germany
mailto:carsten@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: