[SR-Users] rtpproxy bridge "ie" "ei" behind NAT (like in aws EC2)

[Daniel-Constantin Mierla]

Hello,

rtpproxy doing bridging requires two network interfaces to work with.

You can try one of the following:
- let freeswitch advertise the public ip for media and skip rtpproxy
completely
- use the second parameter of rtpproxy_manage() to set the advertised ip
address for media and don't configure rtpproxy in bridge mode

Cheers,
Daniel

On 16/02/15 17:30, Giovanni Maruzzelli wrote:
> dear Kamailians,
>
> I have Kamailio+rtpproxy in front of FreeSWITCH.
>
> Kamailio and FreeSWITCH are on the same private network.
> Public Internet IP address ports are redirected to Kamailio and
> rtpproxy (same situation as in Amazon EC2).
> Clients comes from Internet, and make calls to Internet, SIP signaling
> passing through FreeSWITCH (eg: A leg incoming INVITE, FreeSWITCH
> originate an outbound B leg INVITE, and then bridge the legs).
>
> Using rtpproxy with -A "advertise" patch from Daniel, this topology
> works fine in a "traditional" telco way: rtp goes from caller to
> rtpproxy to callee, and viceversa.
>
> Now I want to maintain FreeSWITCH in the middle of rtp flow all the
> time, in a pure b2bua way, so it can control and analyze the media
> streams.
>
> So, I need rtpproxy to act paying attention to direction, as in
> caller->rtpproxy->freeswitch->rtpproxy->callee (and viceversa).
>
> Normally I would use Kamailio multihomed and rtpproxy in bridging
> mode. But I cannot have a NIC on the public address.
>
> How I can use the "ie" "ei" feature of rtpproxy in an Amazon-EC2 like
> environment? (eg: no public address attached to machine, but ports
> redirection from public address).
>
> I read this trick from Hugh Waite:
>
> "I have used rtpproxy (with the advertised address patch) in Amazon to
> bridge media between internet facing and private subnets in a VPC.
> I found that I couldn’t use different advertised addresses depending
> on which direction the signalling was going on a single private IP
> address. I worked around this by allocating a second private ip
> address to the instance and used that in the ‘bridge’.
> -A 54.86.X.X/10.0.1.15 –l 10.0.1.10/10.0.1.15"
>
> Can you explain how to use this trick, or another way (without
> additional addresses is gladly accepted!) to reach the same result
> (rtp always passing through FreeSWITCH) ?
>
> Thank you all in advance,
>
> -giovanni
>

-- 
Daniel-Constantin Mierla
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio World Conference, May 27-29, 2015
Berlin, Germany - http://www.kamailioworld.com