Instant Messaging

Service Architecture

Instant Messaging has a federated architecture that allows companies to administer their own Exchange Instant Messaging infrastructure, yet allows communication between companies. Businesses can choose to limit their users to instant messaging within the organization, or allow users to send instant messages to other users across the Internet. This enables business-to-business use of Instant Messaging.

An Instant Messaging Service configuration is characterized by:

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This is an example of a simple Instant Messaging configuration, with:

Instant Messaging Servers

Instant Messaging uses two types of servers:

Instant Messaging routers do not host users, but instead refer messages to other servers on the network. In fact, Instant Messaging Service specifically prevents Instant Messaging routers from hosting user accounts. Large companies that deploy Instant Messaging typically use several Instant Messaging routers to accept external and internal messages.

Instant Messaging Domains

It is recommended that you configure your Instant Messaging domains to have a one-to-one correspondence with e-mail domains; for example, users with an e-mail address of @nwtraders.microsoft.com are hosted in the Instant Messaging domain @im.nwtraders.microsoft.com. Because an Instant Messaging router can answer queries arriving at only one Instant Messaging domain, at least one Instant Messaging router should exist for each e-mail domain.

Internet Capability

When an Instant Messaging Service is used only on a corporate intranet, the entire Instant Messaging structure is located behind a firewall. If, however, your Instant Messaging Service is Internet-capable, the inbound Internet connection might be one of these:

The outbound Internet connection might be one of these:

Related Topics

Instant Messaging Domains User Addresses and URLs Instant Messaging Topologies