[Freeswitch-users] High availability on different networks

[Stanislav Sinyagin]

there is an issue with anycast routing though: when you bring up a new
server, some running sessions will be dropped, because their IP
packets would be routed to a different host. So, it needs a careful
design. Maybe place only the SIP proxy on an anycast address, and run
the calls from unique local addresses.


Multiple DNS SRV records with different priorities are also possible,
but you can't direct the users to the nearest location within the same
domain. Also a bunch of SIP clients needs to be tested and you need to
answer the questions, like:

-- what is the timeout if the primary server is unavailable?
-- if the primary host goes down during the call, how soon can the
client re-dial?
-- what happens if the primary server comes up again?






On Thu, Feb 11, 2016 at 8:00 PM, Stanislav Sinyagin <ssinyagin at gmail.com> wrote:
> hi Emrah and all,
>
> it's the first time I actually searched for it, but there are hosting
> offers with anycast IP routing. It means, you have multiple servers in
> various locations, and they share the same service IP address. The
> clients connect to the nearest server, which is determined by standard
> BGP routing. You are still limited to a single global hosting
> provider, but you benefit from its redundant network and geographical
> distribution.
>
> In case of anycast addressing, incoming connections will be served
> easily. But the outgoing connections are rather tricky: you will need
> to bring the outbound call to the physical server where the user has
> registered, and initiate the connection from its anycast address. So,
> you can share and replicate the registration database, but you need to
> send the outbound call to the server which accepted the registration.
> I guess you should be able to retrieve this information from the
> registration database. This needs to be looked in details.
>
> Google for anycast server hosting, and there are at least 3 providers
> offering virtual hosts, and OVH is offering physical hosts as well. I
> guess there are more providers with similar offerings.
>
>
> Without anycast, you would need to use redundant registrars sharing
> the same service IP address -- for example, Digitalocean offers such
> service within any single datacenter.
>
> Having multiple registrars with different IP addresses is also
> possible, but then you depend on the way how each particular SIP
> client handles multiple IP addresses after resolving the domain name.
> Some of them may get stuck to a single address, even if it's not
> responding.
>
>
> cheers,
> stanislav
>
> On Thu, Feb 11, 2016 at 5:53 PM, Emrah <lists at kavun.ch> wrote:
>> Hi list,
>> I’m writing to gather your thoughts and suggestions on how to have a high availability FS setup on different networks.
>>
>> I am trying to achieve the following:
>>  - Load balance FreeSWITCH instances on 2 or more servers, possibly in different countries.
>> - Shared user directory and dialplan, but I’m not sure if shared registrations would make sense.
>> - If a server goes down, the phone should register on the alternative servers. Obviously we can’t keep calls up.
>>
>> I’m obviously not the first one out there doing this. I’m trying to learn from those who’ve come up with reliable solutions.
>>
>> I’ve tried sharing a registration table among multiple FS instances. But it was a beginners mistake. Even with the right path to reach the client, only the invites sent from the server used by the phone would be processed.
>> If my phone registers on server A, then server A shares the info with server B, server B knows how to contact the phone but it won’t be able to. Supposedly because of NAT issues.
>>
>> I am aiming for fully independent FS instances that can back each other up and be used independently. I am guessing this would require some sort of SBC or external registrar server with a Kamailio or Repro.
>>
>> Anyway just trying to spark the conversation around this subject and hopefully we can come up with a formula that can help many with their FS deployments. My provider’s network just went all down in IPv4 and HA behind the same provider proved to be useless.
>>
>> Best,
>> E
>> _________________________________________________________________________
>> Professional FreeSWITCH Consulting Services:
>> consulting at freeswitch.org
>> http://www.freeswitchsolutions.com
>>
>> Official FreeSWITCH Sites
>> http://www.freeswitch.org
>> http://confluence.freeswitch.org
>> http://www.cluecon.com
>>
>> FreeSWITCH-users mailing list
>> FreeSWITCH-users at lists.freeswitch.org
>> http://lists.freeswitch.org/mailman/listinfo/freeswitch-users
>> UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users
>> http://www.freeswitch.org