Office Communications Server User Services
Office Communications Server User Services persists and maintains presence data for registered users and user endpoints. When a user requests registration with User Services through a SIP REGISTER message, it and its endpoint (a SIP-enabled device or client process) are enrolled as authentication permits. The length of time for which registration persists is configurable, as are the number of endpoints allowed per SIP user and the duration of presence subscriptions (where the user subscribes to another registered presence and receives updates regarding its availability).
In Live Communications Server 2003, a server with User Services enabled was called a home server. A user registered with a home server was said to be homed on that server. The equivalent to the single home server in Office Communications Server 2007 R2 is a stand-alone Standard Edition Server with its own MSDE database. In an Office Communications Server 2007 R2 Enterprise Edition pool, the "homing" of users is distributed among multiple home servers, all connected to a centralized Back-End Database Server.
One additional server role in which User Services is enabled is the Office Communications Server 2007 R2 Director. Directors are used only in deployments that enable outside-user access. The role of the Director is not to home users, but to authenticate outside users and route their messages to the appropriate pools.
The settings for User Services are configured with the MSFT_SIPESGlobalRegistrarSetting WMI class.
The basic settings for Office Communications Server home servers and load balancers are configured through the MSFT_SIPESServerSetting class.
The settings for an individual SIP user homed on an Office Communications Server server are configured with the MSFT_SIPESUserSetting class. This user will have the contact presences it subscribes to associated with it as instances of the MSFT_SIPESUserContactData class, possibly grouped with instances of the MSFT_SIPESUserContactGroupData class. Access controls for a specific SIP user are set with an instance of the MSFT_SIPESUserACEData class.
Routing for homed users is defined by the single instance of the MSFT_SIPEsEmSetting class.