Server Roles
Each server running Communications Server 2010 runs one or more server roles. A server role is a defined set of Communications Server functionality provided by that server. You do not need to deploy all possible server roles in your network; you install only the ones for the functionality you want.
Even if you are not familiar with server roles in Communications Server, the Planning Tool can guide you to the solution of what servers you need to deploy, based on the features you want. This section gives a brief overview of the server roles and the general features they provide
· Front End Server
· A/V Conferencing Server
· Edge Server
· Mediation Server
· Monitoring Server
· Archiving Server
· Director
For most server roles, for scalability and high availability you can deploy pools of multiple servers all running the same server role. Each server in a pool must run an identical server role or roles. Some types of pools in Communications Server must have a load balancer deployed to spread traffic between the various servers in the pool.
Front End Server
The Front End Server is the core server role, and runs many basic Communications Server functions. It is the only server role required to be in any Communications Server deployment. Front End Server includes the following functionality:
· User authentication and registration.
· Presence information and contact card exchange.
· Address book services and distribution list expansion.
· IM functionality, including multi-party IM conferences.
· Web conferencing and application sharing (if deployed).
· Application hosting services, for both applications included with Communications Server (such as Conferencing Attendant and Response Group Service) and third-party applications.
· Application services Enables application hosting and hosts applications (for example, Response Group Service, and several others).
· Additionally, one Front End pool in the deployment also runs the Central Management Server, which manages and deploys basic configuration data to all Communication Server computers. The Central Management Server also provides Communications Server Management Shell and file transfer capabilities.
A/V Conferencing Server provides A/V conferencing functionality to your deployment. It can be collocated with Front End Server, or deployed separately as a single server or A/V Conferencing Server pool.
Edge Server enables your users to communicate and collaborate with users outside the organization’s firewalls. These external users can include the organization’s own users who are currently working offsite, users from federated partner organizations, and other external users that have been invited to join conferences hosted on your Communications Server deployment. Edge Server also enables connectivity to public instant messaging (IM) connectivity services, including Windows Live, AOL, and Yahoo!.
Mediation Server is a necessary component for implementing Enterprise Voice and dial-in conferencing. Mediation Server translates signaling and, in some configurations, media between your internal Communications Server infrastructure and an Internet Protocol/Public Switched Telephone Network (IP-PSTN) gateway or a Session Initiation Protocol (SIP) trunk.
Monitoring Server collects data about the quality of your network media, in both Enterprise Voice calls and A/V conferences. This information can help you provide the best possible media experience for your users. Additionally, it collects usage information (call detail records, or CDRs) about various Communications Server features so that you can calculate return on investment of your deployment, and plan the future growth of your deployment.
Archiving Server enables you to archive IM communications and meeting content for compliance reasons. If you do not have legal compliance concerns, you do not need to deploy Archiving Server.
Directors can authenticate Communication Server user requests, but do not home user accounts, or provide presence or conferencing services. Directors are most useful in deployments that enable external user access, where the Director can authenticate requests before sending them on to internal servers. Directors can also improve performance in organizations with multiple Front End pools.
In prior versions of Office Communications Server, you deployed a Standard Edition Server or Enterprise Edition Front End and disabled unneeded Office Communications Server services on the machine serving as a Director. In Communications Server 2010 only the services required for the Director role are installed.
