[Serusers] SER-routing-problem

Hello. I have just installed SER on RedHat 9 Linux with the purpose to route voice packages between a PSTN Gateway AS5350 and a Grandstream HandyTone 286.Letme tell you how it should work: I have assigned a phone number, that when it is picked-up, the IVR from the AS5350 router respods and after the press of a key it sends the packages to the HandyTone and from there to a normal phone; So far so good because it partialy works, that means that the phone rings butt there is no voice. I have managed to solve this problem using a hardware Sip Server between the two devices ( in this way both HT286 and AS5350 act as clients), but this is not possible any more because it was not my server; so i have tried with a software solution and I've installed SER. As I said before , I haven't managed to configure it to work as I wish and this is why I'am asking for your help; it would realy help me if you can provide a ser.cfg example that would do just the routing part (no ack no authentification , no mysql,...., just routing). Please excuse my bad english. Thank you very much !