Voice Messenger (like MSN)

Coders... I need a messenger client (and server) which provides ability to talk (voice) to others, just like MSN, but... it's for local/private network. I don't want to use MSN because it relays through internet/public network. Our network is Windows-based architecture. Any suggestions are welcome. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Complete ownership and distribution copyrights to all work purchased. ## Platform Windows 2000 Adv Server, Windows 98, ME, XP