SBS: Fax Server Is Unable to Properly Receive Faxes

• Microsoft BackOffice Small Business Server versions 4.0, 4.0a, 4.5

SYMPTOMS

When you try to use a Small Business Server (SBS) Fax server to receive faxes, faxes may randomly be received in an incomplete state. Also, the following entry may be added to the application event log:

Source: NT Fax
Event ID: 8218
Description: An error was encountered while receiving a fax. Please wait a minute and have the sender try again. If difficulties persist, please check that the following items are working: Phone line, Sending Fax Device, and Receiving Fax Device. If problems persist, contact product support.

CAUSE

This problem can occur because the fax server utilizes a T30 protocol for transmitting and receiving faxes. The T30 protocol is extremely time sensitive, and has several hard coded time-out values. If the fax threads that operate the T30 protocol do not run within a certain time period, the incoming fax may not be received, and may generate a timeout error message. Microsoft Windows NT Server is not a real-time operating system. There is no way to guarantee that a thread will run within a specified time slice. The fax threads may be preempted by other threads running on the computer and cause a timeout failure on the received fax.

RESOLUTION

To try to work around this problem, increase the performance of the server by increasing the CPU speed or by off-loading some of the server services and functions to other computers or servers.

STATUS

Microsoft has confirmed this to be a problem in BackOffice Small Business Server.

Additional query words: smallbiz sbs

Keywords : kberrmsg kbtool
Version : winnt:4.0,4.0a,4.5
Platform : winnt
Issue type : kbprb