There is more to federation than just allowing partner enterprises to exchange instant messages. There are also conferencing services that enable partnering organizations to host a meeting on one or the other’s infrastructure where they can present content, such as Office PowerPoint presentations. Externally, this is the Live Meeting service that Microsoft hosts for customers that includes the ability to host audio and video, such as real-time discussions using microphones, Web cams, or the Microsoft RoundTable device.

For meetings of this type, an allowance is made for anonymous users. Each must have a conference invitation (made up of a URL or URI that has session information, location information, and an invite key) to successfully join the conference.

Although the requirements for federated users with verifiable credentials are not too different, they have the following characteristics:

As mentioned in more detail in Chapter 6, terminology has changed from Office Communications Server 2007 as it relates to conference types. Open authenticated is now known as Invite Within Network, closed authenticated is now Invite Within Network (Restricted), and allow anonymous is now Invite Anyone.

Verifiable credentials means that you are an authenticated member of the domain in which the meeting is hosted or you are an authenticated member of a partner domain. The fact that you must be authenticated to your home domain prevents you from being an authenticated member from a nondomain location (such as a kiosk or another computer that is not in your company domain).