[OpenSIPS-Users] Opensips geographic redundancy

[Marcello Lupo]

Hi to all,
i have a problem and hope someone can give me a clue on it.
We have an Opensips infrastructure with heartbeat HA and it is working fine.
I'm implementing the geographic redundancy on our VoIP infrastructure with opensips 1.6.4.
There are 2 different locations. 2 server in each location (one running the Opensips and the other running the mysql DB).
The 2 structures are totally independent but share the same DB data (with mysql master->slave->master replication). So each location can handle customer requests independently, the registrations are duplicated from one server to the other to maintain all the CPE's reachable from both servers.
Now I'd like to use the DNS SRV records to let the CPEs to use the 2 servers in a kind of load balance.
I discovered that lot of CPE are not implementing the SRV records logic in a correct way.

Patton CPE with 5.7 firmware make the first REGISTER (without authentication) on one server and after the server answer back with 401 Unauthorized the CPE retry the REGISTER (with authentication) on the other server that reject it because an invalid nonce is found (it was generated from the other server obviously). It should continue the session with the same server it started with the first REGISTER because it received an answer and the server is alive.

Asterisk 1.6 is making the REGISTER properly (one for each server) but place all the calls through only one server even if it is down.

I'm sure will find that lot of other CPE will have trouble with SRV records correct implementation.

I'd like to find a way to do it in a CPE software independent way.
So i'm starting to search another solution that let me implement the geographic redundancy without the SRV records but I'm short of ideas now without inserting any Single Point of Failure in the system.

I thought to a front end proxy (in HA redundancy like the one of now) to be a load balancer to the other 2 proxies but in any way i don't' have a geographic redundancy.

Have you any suggestions?
Thank you all.
Regards,
Marcello