[SR-Users] Kamailio + rtpproxy talking to multiple carrier gateways - some via Firewall/NAT

[Alex Balashov]

On 09/03/2011 05:53 PM, Sarat C. Vemuri wrote:

> 3.Using request_route_preset(“publicIP”)
>
> The above “mostly” works. By that I mean, the INVITE transaction is
> properly passed between internal UAS and carrier SBC and the call is
> setup. However, further transactions (BYE/re-INVITE) etc do not work
> properly. So, far-end hangups are not working etc.

So in other words, there is no interface to which Kamailio could be 
bound on a network that both the UAC and the UAS have direct network 
and transport-layer reachability to?

If I understand correctly, it sounds like the fundamental problem here 
is that the Record-Route URI introduced by the proxy in handling the 
initial INVITE request has to be conserved in all subsequent requests 
and replies.  It is a requirement to use the same route set in 
sequential (in-dialog) requests such as reinvites or BYEs.  It is also 
mandatory for the UAS to copy the received Record-Route into the final 
reply (i.e. 200 OK).

The problem is that you then have to choose the network address in the 
Record-Route.  If either the UAC or the UAS cannot directly reach it, 
your problem arises.

Is this an accurate statement of the problem?  I wanted to verify 
before continuing.

-- 
Alex Balashov - Principal
Evariste Systems LLC
260 Peachtree Street NW
Suite 2200
Atlanta, GA 30303
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