"Greenwich" to Support Windows IM, Real-Time Communications

Instant messaging (IM) will move out of Exchange and into the Windows server operating system when a new service, code-named Greenwich, is released for Windows .NET Server in 2003. An accompanying set of APIs will enable other applications to look up a user’s presence information in Greenwich—that is, to see which device is currently in use and whether the user is willing and able to communicate immediately—and then establish the appropriate type of communication session. However, Greenwich will only support point-to-point communication sessions, meaning that customers interested in multiparty conferencing will need additional products.

Like the Windows Messenger client that was released with Windows XP, Greenwich will use Session Initiation Protocol (SIP), a protocol defined by the Internet Engineering Task Force (IETF) for establishing, modifying, and terminating communication sessions over IP networks. SIP has gained acceptance from major vendors such as Cisco and IBM because it can be used to set up any type of communication session, including voice, video, or data, and can be used to implement presence detection across many types of devices, among other benefits. Microsoft eventually plans to standardize all its real-time communications products on SIP.