Instant Messaging

User Addresses and URLs

Instant Messaging Service identifies its users by unique Instant Messaging URLs, which follow the standard conventions for Web URLs. The RVP protocol the service uses refers to all its users by these URLs.

Because users need a more convenient format than URLs to identify themselves and other users, users always use Instant Messaging addresses to identify each other. The format of an Instant Messaging address is the same as a standard Simple Mail Transfer Protocol (SMTP) e-mail address, although it may not be identical to an actual e-mail address. A user can have more than one Instant Messaging address that refers to the same account, but the user always has one unique Instant Messaging URL.

Users have been using e-mail addresses for a long time, and because administrators would rather not introduce another type of address, Instant Messaging allows the use of standard SMTP addresses as Instant Messaging addresses in most situations. For example, a user whose SMTP address is someone@microsoft.com might be known to the service as http://im.microsoft.com/instmsg/aliases/someone/; however, other users can refer to this user by the Instant Messaging address, someone@microsoft.com. Some situations may require the use of the more fully qualified Instant Messaging address (referred to as the extended Instant Messaging address), someone@im.microsoft.com.

How E-Mail Addresses Are Mapped to URLs

Instant Messaging allows users to refer to each other by their SMTP addresses, but internally uses the corresponding unique Instant Messaging URLs. Clients convert Instant Messaging addresses in the following way: an Instant Messaging address of user@domain is converted to the Instant Messaging URL http://im_domain/instmsg/aliases/user/. The service uses the Domain Name Service (DNS) service location (SRV) resource record to look up the im_domain portion that corresponds to a given domain.

Related Topics

Instant Messaging Domains Give Users Access to the Service