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.

(For more background on Windows Messenger and SIP, see "Windows Messenger Moves IM, Conferencing in New Direction" on page 8 of the Aug. 2001 Update.)

IM for Business; RTC Platform

Envisioned as an add-on service for Windows .NET Server, Greenwich will probably be delivered as part of a feature pack for Windows .NET in the second or third quarter of 2003. However, the company has not decided whether it will charge extra for Greenwich or offer it for free, like Internet Information Services (IIS, Microsoft’s Web server) and SharePoint Team Services (a product for setting up intranet sites).

Microsoft has two goals with Greenwich: to make IM more useful to businesses and to provide a foundation for ISVs and Microsoft to build real-time communications capabilities into a wide variety of applications.

IM for businesses. IM can be a useful tool for employee communication, but employers often block access to public Internet-based IM services, such as MSN Messenger or AOL Instant Messenger (AIM), on security and productivity grounds: messages travel unencrypted over the Internet, and workers could waste time chatting with personal contacts outside the company.

To address this problem, Microsoft introduced IM functionality in Exchange 2000, allowing companies to set up private IM systems. Users' contact lists were stored on the client, presence information was stored within Exchange, and messages stayed behind the firewall. However, Exchange IM does not use SIP, the protocol Microsoft intends to support going forward. Consequently, Microsoft is discontinuing IM in "Titanium," the next release of Exchange due in mid-2003, and moving it into Windows Server with Greenwich.

Microsoft says that Greenwich will also improve manageability and security compared with Exchange IM. For example, administrators will be able to determine whether Greenwich can route messages freely to any other SIP server or must restrict messages to specific domains. In addition, Greenwich will be able to work with TrustBridge, Microsoft's forthcoming authentication gateway, to authenticate IM contacts outside a company and prevent employees from inadvertently sharing confidential information with a "spoofed" contact. (For background on TrustBridge, see "TrustBridge to Simplify Resource Sharing" on page 13 of the Aug. 2002 Update.) Greenwich will also feature logging capability for instant messages, which Exchange IM lacked but is often required for legal purposes.

Microsoft hopes that Greenwich will drive demand for Windows .NET Server while staving off competitors. IBM's Lotus Sametime currently leads the corporate IM market with more than 7 million end-users (according to the company), and Yahoo plans to release Yahoo Messenger Enterprise Edition, a corporate IM product that will integrate with software from Microsoft competitors, such as BEA Systems, Novell, Oracle, and Sun, in early 2003. AOL is also reportedly considering a corporate IM offering, although these plans seem to have been delayed by the merger with Time-Warner and other business concerns.

Platform for real-time communications. One of the most appealing features of IM is presence—the ability to see which computing device a user is using and the user's current status (e.g., "online," "busy," "do not disturb"). This is particularly important for other applications that offer synchronous communication over IP networks, such as video conferencing, Voice over IP, and shared whiteboard applications. Microsoft applies the umbrella term real-time communications (RTC) to this type of synchronous communication, and the final name for Greenwich is likely to be RTC Server or RTC Services.

Greenwich will allow presence information to be stored in the operating system rather than in Exchange—an application that is not as widely deployed—and Microsoft will release a set of APIs toward the end of 2002 so that other applications can exploit this information. For example, a sales force application could tap into Greenwich to determine whether a salesperson is using Windows Messenger for IM or talking on a SIP-enabled mobile device. The application could then use Greenwich to set up the appropriate type of communication session (text or voice) with the appropriate location.

Other Microsoft products such as Office and the Business Solutions Group applications (e.g., Great Plains, MSCRM) will probably use the Greenwich APIs to incorporate these capabilities in the future.

Greenwich Not Multipoint Solution

The first version of Greenwich cannot function as a multipoint control unit (MCU), meaning that it supports only one-to-one communication sessions rather than group sessions. That makes it unsuitable for multiparty communication, such as conference calls, video conferencing, or text chat.

Customers who want this kind of multiparty functionality have the following options:

Use existing Microsoft solutions that will be phased out. Microsoft will continue to offer and support Exchange Conferencing Server—an add-on to Exchange 2000—and the accompanying NetMeeting client. However, these products use protocols (H.323 for audio and video and T.120 for data) that are more complicated and less versatile than SIP. Because of this, Microsoft has stopped development on these products and will eventually phase them out (although the company has hinted that NetMeeting might reemerge as a different kind of collaboration application).

Wait for partner solutions or version 2. Microsoft expects that ISVs in the RTC space, such as Latitude and Radvision, will use the new APIs to build MCUs that run on Greenwich. If no third-party solution appears, the next version of Greenwich might function as an MCU, or Microsoft could release a separate MCU product that runs on the Greenwich platform in the same time frame. But the next version of Greenwich is unlikely to appear until mid-2004 at the earliest.

Adopt a different SIP-based platform. Vendors such as IBM and Indigo Software offer SIP-based systems with multipoint capability for Windows (as well as Unix), but these solutions are not based on Greenwich technology and customers will have to pay for them, whereas Greenwich might be offered for free with Windows server.

Resources

For more information on SIP, see www.sipcenter.com and www.sipforum.com.

Indigo Software is at www.indigosw.com.

Latitude is at www.latitude.com.

Radvision is at www.radvision.com.