The concept of establishing realtime contact across a network existed well before AOL and MSN Messenger Service made Instant Messaging (IM) a part of online culture. Since the late 1970s, many OSs have supported some facility to let users exchange messages in realtime. My introduction to such a tool came when I first started working with VMS and discovered VAXPhone, which let users dial one another across a DECnet network. If the user you contacted was logged on, that user could accept the call, and a two-way conversation ensued. Other users could join the call in a primitive form of online conferencing.
IM is now popular, perhaps because of the number of people likely to be online and available to converse at any given time. According to its supporters, IM lets people exchange dialogue dynamically. IM is more spontaneous than email and less expensive than videoconferencing. And IM provides presence information, which lets users know when a correspondent is available and can help users avoid talking to voicemail.
Currently, interoperability among IM applications is poor, although ongoing discussions are focusing on using either the Instant Messaging and Presence Protocol (IMPP) or the open-source Jabber protocol as the basis for future cooperation. Microsoft was a late entrant in the IM race, but Exchange 2000 Server and Exchange 2000 Enterprise Server include the Exchange IM service—part of the new functionality that somewhat justifies the increase in Exchange 2000 pricing.
All in the Delivery
Exchange IM is easy to deploy, makes only lightweight changes to user desktops, and generates no user data that you must back up or restore. The service doesn't compete with AOL or Yahoo!; MSN Messenger Service targets those products' large, widespread IM communities. Instead, Exchange IM seeks to provide a secure mode of instant communication that is well integrated with a company's internal IP network. As such, the service competes with products such as Lotus Sametime and Tribal Voice's PowWow. Microsoft based the Exchange IM client on the standard MSN Messenger Service client and added code to integrate the client with Exchange 2000. Exchange IM offers the following features, which combine email's functionality and the telephone's speed and accessibility.
Realtime messaging. Email transmits and delivers data at an unpredictable future time. With IM, users send and see data immediately.
Contacts. Users can maintain a list of people with whom they want to communicate on a regular basis. IM contacts aren't the same as Microsoft Outlook contacts or Windows 2000 Active Directory (AD) contacts, although you can expect IM contacts and Outlook contacts to merge in the future. IM holds contact information, on a by-user basis, in the Registry on client PCs.
Status tracking and notification. IM tracks users' online status (aka presence information) and reports that information to the users' contacts. The Exchange IM client, which Figure 1, page 150, shows, displays contact and status information. Users can change their status to show whether they're available for a realtime conversation or are otherwise engaged (e.g., on the telephone) and shouldn't be disturbed. Bespoke applications can use the Exchange IM software development kit (SDK) to exploit presence information. (For information about the Exchange IM SDK, see the sidebar "Building Custom Clients and More," page 152.)
As Figure 1 shows, the Exchange IM client also includes a pane that displays advertisements from MSN. Having advertisements pumped down your throat can be annoying; to solve the problem, you can use the Exchange IM SDK to create your own client. However, custom-built clients can communicate only with Exchange 2000's IM service. To create an ad-free environment, you can modify two policy settings in the Registry. You must change these settings on every client machine, so I suggest that you use a tool such as Microsoft Systems Management Server (SMS). To eliminate the advertisements, go to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ MessengerService\Policies Registry key. Set the Disable
CrossPromo and ExchangeConn values to 1. (These changes disable the advertisements, but you can't remove the MSN logo that displays when the client starts.)
To prevent clients from using the standard MSN Messenger Service (and thereby restrict their IM communications to Exchange 2000 users only), you can set the ExchangeConn value to 2. To display a warning message when the client starts, you can modify IMWarning. For example, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MessengerService\Policies\IMWarning "Don't be silly—keep credit card information to yourself!" will remind users not to send credit card numbers to IM correspondents.
Privacy. Users can decide who can view their online status or communicate with them. Users can also see who asks for or receives their status information.
You've Got (Less) Email
Apart from the ability to support realtime conversations, Exchange IM's most attractive aspect is the chance to eliminate some of the mailbox-cluttering staccato-type email exchanges that happen today. The following exchange is a typical example:
User 1: Hello? Are you in today?
User 2: Yes, do you want to talk to me?
User 1: That'd be great. When are you available?
User 2: I should be free at 11:00 a.m. or at 2:00 p.m. What's good for you?
User 1: I can't make either time. Could you come to my office for 10 minutes now?
User 2: Sure. Let me clear up a couple of things and I'll be there in 5.
User 1: Great. See you then.
Seven messages make up this message thread. From a systems perspective, seven messages now clutter up mailboxes—perhaps on two servers—and each message probably contains all the text from the preceding items.
Exchange IM uses fewer system resources for these types of communications and, best of all, leaves no trace of the finished conversation, eliminating long-term data retention. This elimination brings us to another facet of Exchange IM. You might think that IM is most interesting to the technical community, but senior managers can also get a lot of value from this technology. Users can discuss potentially sensitive topics (such as those featured in some recent high-profile court cases) without the fear that their words will come back to haunt them. (Indeed, Bill Gates probably wishes he'd used IM for some of his past communications with senior managers.) The potential benefits are obvious, although Microsoft might need to add an optional method to record IM conversations in industries that require monitoring (e.g., financial trading).
Additionally, most senior managers don't have a lot of free time, and personal assistants monitor these managers' mailboxes and closely schedule their time in the office—complicating your efforts to get a slot on the manager's agenda or a quick answer to an email message. If managers log on to IM, their contacts (e.g., their staff, employees who report to them directly) might be able to use IM to speed up decision-making processes.
The primary problem with Exchange IM is its total lack of integration with Outlook. Exchange 2000 holds IM contacts in the Registry and offers no support for linking IM contacts and Outlook contacts. The gap in development deadlines between Exchange 2000 and the next major release of Microsoft Office is largely to blame for this problem, so you can expect the next iterations of IM and Outlook to be much more integrated. Microsoft might also release a COM add-in for Outlook to bridge the gap between IM contacts and Outlook contacts, but at the time of this writing, that code hasn't yet materialized.