Domain Controller - Global Catalog sizing for OCS deployment RRS feed

  • Question

  • When deploying Exchange a design rule of thumb exists for sizing global catalog servers. The amount of global catalog server processor cores is related to the amount of mailbox server processor cores.


    Is there a similar design rule for deploying OCS servers?


    Some facts and figures:

    We are deploying IM/Presence for 18.000 users from one data center. We are deploying conferencing (audio, video and web) first as a pilot for max. 50 users, also from one data center. There are two OCS FE servers in a consolidated setup and one SQL server.


    We already have Exchange 2007 running is this data center and the amount of domain controllers/global catalogs is based on Exchange.


    Client are spread all over the world, spread over 200 physical sites and for the most corresponding AD sites.


    Hope someone can help me on this.



    Tuesday, September 23, 2008 9:17 AM

All replies

  • I haven't seen any documentation specifically regarding GC sizing but I would think that if you've already designed GC placement based on Excahnge best-practices, and all OCS users will be Exchange users as well then that design would be fine.  I would think that OCS's leverage of GC lookups is much 'lighter' than what Exchange Server requires.

    Tuesday, September 23, 2008 12:53 PM
  • No additional GC is needed unless you experience issues.. but with 18,000 users, if you get close to 10k concurrency signed in, please add a 3rd FE server.


    Other than that, you are golden.


    Wednesday, September 24, 2008 3:31 AM