Requirements: .NET Framework 3.5 SP1

OfficeSIP Messenger provides enterprises with advanced instant communications for free. Compatible with Office Communications Server 2007, OfficeSIP Messenger delivers reliable performance combined with trouble-free deployment and management. Supporting text, voice and video chats, the free softphone implements ICE, STUN, and TURN protocols to easily traverse NAT and firewalls, and supports TLS for ultimate communication security.

See also easy to use open-source cross-platform messenger Brief Msg.

OfficeSIP Messenger is based on industry-standard libraries used by Microsoft Office Communicator, providing robust, reliable operation in business environment. Thanks to the high-quality code, OfficeSIP Messenger ensures the highest level of compatibility with audio clients and Web cameras, and provides landline-quality calling for both voice and video.

Unlike other enterprise instant messengers and communicators, OfficeSIP Messenger is entirely server-based, allowing administrators to enter, store and modify all settings, configurations, and user profiles on a corporate server. IM users will benefit from a single sign-on after logging in to the corporate domain. Active Directory support allows the IM system getting information about the users directly from the server?s domain controller.

The free enterprise communicator costs nothing, yet provides the level of services not found in its much more expensive competitors. Voice communications are implemented via VoIP using the industry-standard SIP protocol to provide free voice calling no matter whether the recipients are in the same building or on the other side of the world. Single log-on allows softphone users signing in to a SIP server without having to enter a password. The free enterprise instant messenger offers businesses advanced video chat capabilities with easy installation and zero-hassle NAT/firewall traversal.

Most offices are using a single Internet uplink to connect with the world. Sharing a single Internet connection means that a NAT router is often in place. Combined with a firewall, the router can prevent many voice communicators from streaming audio and video. OfficeSIP Messenger implements ICE, STUN, and TURN protocols to easily traverse NAT and firewalls with no additional configuration required on either side. TLS support ensures that all communications are securely encrypted, and cannot be intercepted by a third party.