__________________________________3.5.  FDDI      235

        
  ,    DAS,    -
    (Optical Bypass Switch), 
        , 
   .

 ,  DAS   DAC    
     ,    
   .      
,     .     Dual
Homing

       SMT
         -
,           .
  FDDI         
,          -
  ,     .

        -
   ,  -
       .

3.5.4.    FDDI

  FDDI        -
   4/5     -
 NRZI.           
 125 .

   32  5-    
4-    16 ,    16 
 ,    .    -
    Idle  ,   -
         .   
    FDDI     -
    .     
Idle        -
    ,   .

         -
    .    -
     4/5,   
     .   
       (, ,   S)  , 
   (,  S-S    . .).
  ,        -
   4/5,      MAC
      MAC.   
 ,     .  
      -
 SMT.