Hello all.

We are facing some problems in our deployment of OpenSER, related to NAT Traversal solution using MediaProxy.

In our scenario, using the the sample configuration NAT detection works right for REGISTER method, and for INVITE's sent from clients behind NAT, but, incoming calls originated from transparent clients, directed to clients behind NAT do not work, and do not pass through MediaProxy. Services based on re-INVITES do not work either.

To solve that issue, we tried to intercept the 200 OK answer coming from NAT client, so that we could call use_media_proxy(), but, we get the error: "Empty Response from media_proxy()"

Our configuration is more or less like this:

# In the beginning of the main route

if(client_nat_test("7"))
{
   setflag(2);
   fix_contact();
};

.....

if(is_method("INVITE"))
{
    if(isflagset(2))
    {
        use_media_proxy();
    };

    t_on_reply("1");

}

....

on_reply_route[1]
{
        if (status =~ "(18[0-3])|(2[0-9][0-9])|(1[0-9][0-9])")
        {
                if (client_nat_test("3"))
                {
                        fix_contact();                      
                        use_media_proxy();
                }

        }
}


That is a very brief configuration fragment, but it is more or less the schema of configuration we are using. So far, our solution to be able to have the whole services working is marking all the calls so that they pass through the mediaproxy, but we are not sure if that is a good solution.

Thanks in advance for every hint or suggestion.

Kind regards

Sergio Armando Gutiérrez Betancur
Subdirección Aplicaciones de Servicios Convergentes  
UNE - EPM Telecomunicaciones
 Tel: 054 3802956
Email: saguti@gmail.com