Director Role in LCS & OCS (Part 1 of 3)
One of the server roles with LCS 2005 SP1 and now with OCS 2007 that is often overlooked is the director. What we take a look at in this two part blog is why director is recommended, topologies that are available with the director, and planning once the director is in place.
So let's begin by answering that question that so many of us ask, "Why do I need a director?"
The director server is a server role that can be deployed in standard or enterprise deployments. The director comes into play when a deployment of LCS or OCS has remote users or federation activity into the organization. The director's mains responsibility is to offload authentication from the existing standard edition or front-end server and onto the director server.
In OCS 2007 there director can be a standard edition server that is responsible for just performing authentication of user request. For that to happen other roles of a standard edition server need to be deactivated such as the web conferencing, web components, a\v conferencing, also deactivate the ABS.
The director really comes in handy when we have a lot of users that will be located on a standard edition server or in an Enterprise pool. The standard edition OCS 2007 server can handle up to 5000 active concurrent users. A collocated enterprise pool can handle up to 30,000 users. With those configurations, the Front-end servers are not just authenticating users but they are also performing other responsibilities as well, such as web conferencing, A\V conferencing, and IIS services as well. By implanting a director the FE server can now concentrate on providing better performance for the responsibilities that it also delivers.
So let’s look at the case where we have a deployment of 4500 users in an organization; the decision is made to deploy a Standard Edition OCS 2007 server. It was determined that approximately out of the 4500 users 3500 would be logged on and active an any point in time. Aside from using IM, you have provisioned a subset of users to leverage the conferencing features of OCS 2007 by allowing them to use A\V and Web Conferencing.
Now we have a need for supplying remote access to the users in the organization as well, so we deploy a collocated edge topology. Now by adding a director into the equation we are able to not have remote (external) users authenticated on the actual single Standard Edition server that we have. In addition the single Standard Edition server does not have to be concerned with authenticating internal users in the organization as well. Those responsibilities have been elevated from the internal Standard Edition server to and passed onto the internal Director server that we have in place.
In the next blog, we will talk about different topologies that are available with the director server with OCS 2007.