nSIP is an RFC 3261 compliant implementation of SIP (Session Initiation Protocol) for .NET, written in C#. nSDP is an RFC 4566 compliant SDP parser also in C#, and can be used to make payloads to nSIP messages or to parse any SDP message.
...The GUI is in JAVA and uses JNI to implement the h323 stack based on OpenH323. It compiles and runs on Linux, and Windows.
Compatible with netmeeting, gnomeeting, cphone, and any H323 Cli