Hi I've setted up a TestBed about ToIP based on SIP. In this TestBed I've used a SER Server running on a Linux Red Hat 9.0. I have had several problems with this TestBed for a long time. I cannot call external phones across the gateway (Cisco 1760). Once the call is established it lasts 20 second, before this time it hangs up. I would like to ask you, if its possible for you to review my configuration in order to detect any kind of mistake or problem. Thanks for all your help Albert