[Kamailio-Users] Having problems using RTPProxy to bridge internal/external networks

[Alex Balashov]

An update on this:  we've gotten the SDP substitution to happen 
correctly using rtpproxy_offer()/answer(), and the media endpoints now 
send their media to the correct respective interface addresses on the 
rtpproxy host.

However, despite allegedly running in "bridge mode" (-l 
one.ip/two.ip), the rtpproxy does not appear to be "bridging" them - 
that is, it is not forwarding.

We previously found that having /proc/sys/net/ipv4/ip_forward on was 
an issue, so we turned it on - but to no effect.

Alex Balashov wrote:

> Örn Arnarson wrote:
> 
>> Oh, I forgot one thing;
>>
>> I'm using fix_nated_sdp, as previously mentioned. I have a hunch that
>> because I'm not using force_rtp_proxy/rtpproxy_offer it's not being
>> relayed (a hunch, because I don't fully understand how rtpproxy
>> works). Problem is though, I can't get the IP addresses correct by
>> using rtpproxy_offer.
> 
> On behalf of Joe (same company) I will add that there is no NAT scenario 
> here.  Both the private and public network are directly routable from 
> the rtpproxy box;  there is no IP address oversubscription, and no 
> reason to ignore ports or addresses in SDP and replace them with 
> received parameters.  This is not a far-end NAT traversal solution.
> 
> What is basically being asked here is how to bridge between two 
> interfaces (internal, external) without NAT using rtpproxy, and if 
> anyone can provide a canonical implementation or example.
> 
> We've got it running in bridge mode, e.g.
> 
>   rtpproxy -F -s udp:10.x.x.x:5050 -l 10.x.x.x/89.y.y.y
> 
> ... and basically, are just wondering how to get this to work on the 
> Kamailio side using rtpproxy_offer()/rtpproxy_answer().
> 
> The RTP proxy machine is a dedicated host;  the SIP proxies are virtual.
> 
> 


-- 
Alex Balashov - Principal
Evariste Systems
Web     : http://www.evaristesys.com/
Tel     : (+1) (678) 954-0670
Direct  : (+1) (678) 954-0671