Communicator 2007 R2 users experience network bandwidth issues

After Microsoft Office Communicator 2007 R2 users are moved from one pool to another pool, the users may experience network bandwidth issues.

When users are moved from one pool to another pool, the Address Book Server (ABS) that they use changes. Although every ABS imports data from Active Directory daily, different ABSs might contain different data because of different Active Directory data import time stamp. Therefore, the delta ABS file from one ABS cannot be applied directly to a Global address list (GAL) database that was created by using the ABS files from another ABS.

When Office Communicator 2007 R2 downloads a new GAL delta file, Office Communicator 2007 R2 checks which of the following conditions is true:

• The BaseFileHash field of the new GAL delta file matches the BaseFileHash field in the GAL full file.
• The BaseFileHash field of the new GAL delta file matches the BaseFileHash field in the previous GAL delta file.
• The BaseFileHash field of the new GAL delta file does not match the BaseFileHash field in either the GAL full file or in the GAL delta file.

If the fields do not match, which occurs when users have moved pool, Office Communicator 2007 R2 downloads the GAL full file instead.

To fix this problem, apply the following update:

After you apply this update, when a mismatch is detected Office Communicator 2007 R2 downloads a GAL delta file that was generated by the new ABS several days earlier. Then, Office Communicator 2007 R2 applies the GAL delta file to the existing GAL database that was created by using the ABS files from the old ABS. By doing that, Office Communicator 2007 R2 makes sure that there is no missing data, and that the redundant data download is minimized.