LCS 2005 Standard Edition System Architecture

Live Communications Server (LCS) 2005 servers may be configured for several roles. All systems need at least one Home Server that communicates with an Active Directory (AD) domain controller and creates special LCS user accounts for AD users assigned to that LCS server. The Home Server also stores the accounts and their associated contacts (“buddy”) lists and allow/block lists in a local MSDE database. Home Servers authenticate users and route messages to other users.

If the organization wants to use LCS 2005’s archival feature, it requires a separate LCS Archiving Server with a SQL Server database to hold the messages and other logged data.

To support federation and remote users, a dual-homed LCS server configured in the Access Proxy (AP) role is needed in the perimeter network, with one interface published to the Internet to communicate with trusted partners or clearinghouse APs using Transport Layer Services (TLS, which uses the Secure Sockets Layer protocol and certificates to provide both data encryption) and, for federating organizations, for mutual server-to-server authentication. Communications between remote clients and APs use TLS encryption to protect against eavesdropping, but the authentication is server-only (i.e., remote user computers do not require certificates). The other AP interface communicates with LCS servers on the organization’s intranet.