Communicator 2007 crashes when the SipCompression registry entry is set to PING mode and the Transport registry entry is set to TLS

Microsoft Office Communicator 2007 crashes when the following conditions are true:

• The SipCompression registry entry is set to PING mode.
• The Transport registry entry is set to Transport Layer Security (TLS).

This problem occurs if the SipCompression entry and the Transport registry entry are set to the following values:

• SipCompression: 3 PING mode
• Transport: 4 TLS

These registry entries are located under the following registry key: The SipCompression registry entry is used to set Communicator 2007 in a mode in which it detects the link speed by approximating packet round-trip latency. Communicator 2007 uses this information to enable SIP compression. This information is useful for certain VPN clients or for network adapters that do not inform the application about link speed.

How to obtain the hotfix

This issue is fixed in the Communicator 2007 Hotfix Package that is dated October 5, 2007. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.