1  echo

   Causes the link subentity to transmit an SMT Echo request
   frame and await the response. If a response is received, it is
   displayed.  

   echo  [node node-id] fddi station station-name link link-index -
         target lan-address, data octet-string [,timeout integer]

   The Target and Data arguments are required.  Target is the 48-bit 
   LAN address of the target node.  Data is the data to transmit in 
   the echo request.  The Timeout argument is optional.  It is the 
   timeout in seconds in the range of 1 to 65535.  The default 
   timeout is 60 seconds.

2  Exception_Messages

o  reject

   Request was rejected by the target station.
 

o  timeout

   No response was received.