XCON: Facilities Data Not Sent Out (by Exchange) with CALL ACC

The Exchange Server computer may be unable to receive any X.25 incoming calls if there is call facilities data in the call packet.

For example, an Eicon trace shows the following: In this trace, the facilities are 420707430404.

• The former digit 06 is the length of the facilities field.
• The fields by themselves have to be split into Code-Byte 1-Byte 2.
  
  The first field means packet size = 128 (42 is packet size code, so the first digit is for remote DTE and the second is for local DTE. In this case, 7 indicates a packet size of 128 bytes).
  
  The second field means window size = 4 (interpreted in the same way as packet size).
• In the CLEAR Packet, the code is 42 (facility parameter not allowed).

The incoming call is accepted by the Exchange Server computer because the facilities in the CALL packet match the facilities set in the X.400 stack, but the calling side drops the connection when it does not see the facilities in the CALL ACCEPT packet.

To work around this problem, do one of the following:

• Do not use Call Facilities data.
• Obtain the following fix.
• Wait for the next Exchange Server service pack.

To use the fix or the service pack, you must add a new registry value.

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

1. Start Registry Editor (Regedt32.exe).
2. Locate the following key in the registry:

      HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
      \MSExchangeMTA\Parameters
   						

   NOTE: The above registry key is one path; it has been wrapped for readability.
3. On the Edit menu, click Add Value, and then add the following registry value:

           Value Name: Use incoming facilities on accept
           Data Type:  REG_DWORD
           Value:       1

4. Quit Registry Editor.

To resolve this problem, obtain the latest service pack for Exchange Server version 5.5. For more information, please see the following article in the Microsoft Knowledge Base:

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5.