sip server

Dear. Hey! I want your OS work with sip server. Can you suggest some sip poxy server. And it must easy to configure and setup because i's very baby adminitrator in linux and freebsd. Thx. Good man

IPV6

plzplzplz i want to make my server(freeBSD) to work with ipv6. but i'm new people for linux operation ( T T ). Can you have how to or handbook for setup my server to ipv6( Step-by-step) . Thx very much