I've successfully implementented an asterisk solution in a small company. They have only 5 computers and 5 ip phones. They have a cable internet access, serving two public ip addresses, one ip to the linux box and the other ip to router. the linux box must have a public ip to serve sip phones outside. It would be much better if I could integrate all those services in the linux box, they, some times, have problems with QoS. I was experimenting with IPCOP, but wasn't able to build asterisk on it. Is there a similar solution to this problem?