I was surprised to recently learn that the Presence functionality typically ranks #3 in bandwidth usage in most OCS 2007 deployments (behind Audio/Video and Application Sharing). The simple act of updating Presence for a contact consumes negligible bandwidth, but when you are dealing with large contact lists (e.g. 50, 150, 200 contacts) with Enhanced Presence, the aggregate bandwidth consumed shows up on the overall bandwidth radar.
If the size of contact list (aka buddy list) is an important variable, how do you know the average contact list size in your deployment, and how can we control it?
Note: the default number of contacts on the server-side is 150, and 1000 on the Office Communicator 2007 client. The lower number will take precedence.
What is your average contact list size?
You can report on the both the Average number of contacts per user, and the Maximum number of contacts per user directly in the OCS management console. Highlight the Enterprise pool (or Standard Edition pool) and select the Database tab. Click the “Go” button for Contact Statistics under the User Summary Reports.
How can you control the maximum number of contacts per user?
The maximum number of contacts any one user can have can be set on the server side, and the client side (Microsoft Office Communicator).
To set it on the server-side:
• For an Enterprise pool, this can be set for all Front-End servers in the Pool: expand Enterprise pools, expand the pool you want to set, right-click Front Ends, click Properties, and go to the General tab.
• For a Standard Edition Server, expand Standard Edition servers, right-click the pool and select Properties, Front End Properties, and go to the General tab.
The set this on the Office Communicator client, there is a GPO settings (MaximumNumberOfContacts), that can be specified. The default is 1000, which is also the maximum that this can be set to. You can find this and other Communicator policy settings here.
