[Asterisk-Users] Connecting to a cluster of SIP servers

[Aaron Daniel]

>> Huh?  Has this happened to you in practice?
>
> It sure has. Polycom phone queries DNS for domain.com and gets round robin IP of 192.168.10.1. It sends a REGISTER request to that IP. Asterisk at 192.168.10.1 sends back a 407 Proxy Auth required. The polycom phone then queries DNS again and gets 192.168.10.2 this time and sends the REGISTER with auth info included this time to Asterisk at 192.168.10.2. The Asterisk at 192.168.10.2 box goes 'huh. What the hell is this for?' becuase it never received the original REGISTER, and drops it on the floor. The phone never gets an OK to its register request.
>
> Doug.

Makes sense.  We only use the round robin records for the outbound proxy, 
so the only time they use the other servers is when they make outgoing 
calls.  As for the registrations, the phones register with a primary 
server and a secondary server (or in the case of the polycoms, if server 
one is down, it re-registers with server two immediately... it works, 
we've tested it), so any server in the round robin group knows about the 
phones when they make outbound calls.

However, I think in the sense of actually MAKING phone calls, once it gets 
an ip address for a round-robined host, it continues talking to that 
host... i.e. Once the phone's in a conversation, all related packets for 
the stream go through the same server, not to any other server in the 
group.


-- 
Aaron Daniel
Computer Systems Technician
Sam Houston State University
amdtech at shsu.edu
(936) 294-4198