[OpenSIPS-Devel] questions about inter-domain roaming

[Thomas Gelf]

zhangchao00001 wrote:
> Hello everybody, I have some questions about Inter-domain Roaming.
> ...
> Here is my experiment environment(the picture above):there are two
> Domains A and B, C1、C2 belong to Domain A, C3 to Domain B, P1 and P2
> are proxy server. C1 roams in Domain B and register to P1 through P2.
> then C2 want to make a telephone to C1...

It doesn't matter where C1 is to be found, it will always be registered
to P1. P1 will be able to reach it, takes care of keepalives, NAT fixes
etc. Both P1 and P2 shall obviously record_route. Doing so C2 will
always be able to call C1 (using it's proxy P1).

If C3 wants to call C1 (belonging to a foreign domain) it shall use P2
as outbound proxy, P2 will look up C1's domain (eventually repecting
SRV records) and send the call to P1. As we learned before, P1 will
be able to contact C1.

There will be no SIP packets from peer to peer, if you allow that (and
don't record_route) you will be lost.

Best regards,
Thomas Gelf

-- 
 mail: thomas at gelf.net
  web: http://thomas.gelf.net/