http://www.rfc-editor.org/rfc/rfc4123.txt
RFC 4123: Session Initiation Protocol (SIP)-H.323 Interworking Requirements, H. Schulzrinne, C. Agboh2005-07-01T23:00:00-00:00This document describes the requirements for the logical entity known as the Session Initiation Protocol (SIP)-H.323 Interworking Function (SIP-H.323 IWF) that will allow the interworking between SIP and H.323. This memo provides information for the Internet community.