Title:  Single-Mode Fiber Modular PMD Connector Types.

     The currently shipping Single-Mode Fiber (SMF) PMD, the DEFXS-BA, uses
     the ST type connector.

     The previous version of the Single-Mode Fiber (SMF) PMD, the DEFXS-AA, 
     used the FC type connector.

     A minimum of 12 dB loss is required for all of Digital's SMF PMD 
     connections.

     When a customer has a mis-match in connector and receptacle
     type, the usual solution is to obtain a hybrid adapter
     cable.  In the example of our DEFXS-BA (which has ST
     receptables) located in a site with FC connectorized cables,
     the hybrid adapter cable should have ST connector on one end
     and FC connector on the other end. The adapter cable would
     be connected to the site cable with an FC coupler, and the
     ST end would be connected to the DEFXS-BA.


     A rough picture is shown.


     DEFXS/ST
              | ST Plug        FC Plug               FC Plug
     +---+             Adapter            Coupler      \/
     |   |              Cable                                Site Cable
     |   +--+     +---+        +---+    +--------+    +---+      \/
     |      | +---+   |--------|   +---+|        |+---+   |-------------
     |      | +---+   |--------|   +---+|        |+---+   |-------------
     |   +--+     +---+        +---+    +--------+    +---+
     |   |
     +---+


 
     Adapter cable and couplers are readily available from many vendors.
     This information is supplied in the FDDI Media Connection Information
     publication (EK-Q0597-MI.001).