Microsoft® Office Communications Server 2007 Resource Kit

Examining the Technical Details Behind the Federation Scenario

A discussion of how federation is accomplished isn't really complete unless there is an in-depth look at the flow of messages and the protocols that accomplish it. So we're going to look at Session Initiation Protocol (SIP) in federation. Because SIP has been discussed at length in other chapters of this book, we won't spend a lot of time on the nuts and bolts of the protocol. But where necessary, we will re-emphasize some attributes that have been covered elsewhere.

Examining How Clients from Two Federated Domains Get Online and Register Presence

First, note that SIP is a signaling protocol—it uses verbs, or methods, much like SMTP does to talk to server processes. And many of the methods ...