On 29 Dec 2014, at 12:13, Ben Langfeld <b...@langfeld.co.uk> wrote: > On 27 December 2014 at 23:44, Carsten Bock <cars...@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.
RFC 2782 says that the target has to be a name which you look up in the next step. I'm not clear that a name can't be an IP address, but there's no example of that. It's an interesting question. I see no reason for adding IP addresses there though. Asterisk fails miserably in DNS SRV support. Been working on fixing that for chan_sip for a while, but the DNS code is really bad and hard to clean up. /O > > 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.b...@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@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:cars...@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/ > > _______________________________________________ > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list > sr-users@lists.sip-router.org > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users > > _______________________________________________ > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list > sr-users@lists.sip-router.org > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
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