Server Roles
The Live Communications Server architecture consists of multiple roles, each serving a different function. Your environment must include one of the first two roles, Standard Edition or Enterprise Edition, which handle the front-end operations of Live Communications Server. These roles function as a "home server" within Live Communications Server architecture. All other roles perform in conjunction with these front-end architecture components.
Standard Edition
Live Communications Server 2005 Standard Edition provides a simple way to enable presence and IM (instant messaging) services for smaller, less complex networks. Standard Edition is completely self-contained and does not require an external installation of SQL Server to operate.
Enterprise Edition
For deployments that require higher availability or greater scalability, the concept of a "home server" is divided into two distinct parts: Live Communications Server Enterprise Edition, which manages client connections, presence, and other real-time communication features like instant messaging; and Live Communications Server 2005, Back-End Database, a back-end server, running Microsoft SQL Server 2000 SP3a (Service Pack 3a), which can be clustered. Together the Enterprise Edition Server and the Back-End Database form a pool.
Users (clients) register on an Enterprise pool. Users are directed to a specific server within the pool by a load balancer that distributes the load to these servers. The load balancer exposes a single VIP (virtual Internet Protocol) address that is used by the clients to access the pool. Each server running Live Communications Server 2005 Enterprise Edition within the pool is responsible for connection processing, security and authentication, protocol processing, and server applications. Static data, such as contact lists and ACLs (access control lists) are stored as persistent data on the Live Communications Server 2005, Back-End Database. A client can register on one server in one instance and a different server at a different point in time, or might have multiple devices where the user is logged on (endpoints)—each logged on through a different server at a single point in time.
The user data is resident in Live Communications Server 2005, Back-End Database, which is a server that runs SQL Server 2000. The database contains records that hold static data previously described and dynamic user data such as endpoints and active descriptions for a user, and runs a set of stored procedure calls that form the core of the operational software. Live Communications Servers within the pool are networked to the back-end server using a high-speed network. These Live Communications Servers also run the UR (User Replicator) service to provide a connection to Active Directory® directory service so user account information can be synchronized from Active Directory to the Live Communications Server 2005, Back-End Database.
Answered by
keshto
at
8:03 PM on June 02, 2008