[SR-Users] Kamailio + rtpproxy talking to multiple carrier gateways
Sarat C. Vemuri
sarat.vemuri at fthco.com
Tue Sep 6 01:59:30 CEST 2011
Sorry about this clumsy way of replying, but I am stuck with Outlook 2010 and Exchange.
You stated the problem correctly. Carrier GWs (UAS) and internal clients (UAC) cannot reach each other directly (TCP/UDP). They have to go through Kamailio and rtpproxy. I am goint to reply to Ovidiu as well with some more details.
Date: Sat, 03 Sep 2011 19:12:38 -0400
From: Alex Balashov <abalashov at evaristesys.com>
Subject: Re: [SR-Users] Kamailio + rtpproxy talking to multiple
carrier gateways - some via Firewall/NAT
To: sr-users at lists.sip-router.org
Message-ID: <4E62B466.20808 at evaristesys.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
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
Atlanta, GA 30303
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