[VoiceOps] Load balancing SIP

[Alex Balashov]

Kamailio provides an excellent and high-performance vehicle for doing 
this. It's probably one of its most canonical use-cases.

You can do it in one of two ways:

1) Use Kamailio as a redirect server with some state.

But this is the more complicated option, and requires that the 
registering endpoints follow redirects for REGISTER requests, which they 
don't always.

2) Use REGISTER pass-thru with the SIP Path extension:

https://tools.ietf.org/html/rfc3327

Kamailio has a specific module for this:

http://kamailio.org/docs/modules/4.4.x/modules/path.html

... and it works great. With a simple config that doesn't have a lot of 
external I/O dependencies, you can handle tens of thousands of 
registrations per second, at least.

-- 
Alex Balashov | Principal | Evariste Systems LLC
1447 Peachtree Street NE, Suite 700
Atlanta, GA 30309
United States

Tel: +1-800-250-5920 (toll-free) / +1-678-954-0671 (direct)
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