[SR-Users] Forwarding registrations upstream

[Spencer Thomason]

Hello,
I'm trying to use Kamailio as a customer facing SBC to handle NAT traversal and basic SBC functionality for a group of backend FreeSWITCH servers.  What I'm trying to accomplish is this:
- UAC sends REGISTER
- Auth is handled by the edge proxy, backend server trusts edge proxy
- If NAT is detected, expires is decreased to 60 seconds, proxy sends options ping
- REGISTER is cached and forwarded upstream with Path header and longer expires, i.e. 3600 seconds
- UAC reregisters every < 60 seconds but upstream registration is only changed if the timer expires (just less than 3600 seconds) or if AoR changes


I good illustration is here:
http://www.markholloway.com/blog/?p=1826

My thought is to use htable to store the AoR with an expires just less than 3600, and check it before crafting a new REGISTER with uac module.  Is there a better way of handling this scenario?

Is there an efficient way populate the $uac_req(…) pseudo variables and call uac_req_send() for multiple, i.e. 4-6 backend servers?  I guess all I would need to change is the RURI?

Thanks,
Spencer