The Ms-diagnostics header passes diagnostic data between servers and clients within the domain. This header is included only in Session Initiation Protocol (SIP) responses and not in SIP requests. If a user experiences an Enterprise Voice issue while using Office Communicator, a message with a specific error code may be displayed in Office Communicator. If the user receives a message but still cannot resolve the issue, use the message and error code to start your own troubleshooting efforts. Ask the user to do the following:

  1. In the message that is displayed in Office Communicator, click Details. If there is an error code, record it.

  2. On the client computer, enable Client Logging in Communicatorand Event Viewer, and then try to reproduce the issue. The event log provides detailed information about the error, including identification of the server that reported the error and any other details, such as the reason that the error occurred.

For details about many common error codes, see Communicator Error Messages at . For details about error IDs and reason values for ms-diagnostic headers, see Appendix A: Diagnostics Header Error ID and Reason Values of the [MS-OCER]: Client Error Reporting Protocol Specification, which you can download from MSDN at .