6.4.            543

         .
     SDH/SONET,    -
.           
 -3 155 /.   Forum     
  SDH,    -3  -12 (622 /).  -
 155 /     - ,
      5.   622 / -
  - ,   SMF,   MMF.

       ,   SDH/
SONET.     1/1  /,   -
 ,         4/5
  100 / (FDDI)     25 /, -
  IBM    Forum.  ,  
155,52 /    cell-based  ,  
,   ,     SDH/SONET.   -
     SDH/SONET,     _
  ,      -
 ,        -
   .

       
 ,     ,      -
   ,     .
        
        
             -
      ,  
         
.

        -
 .        
,      .   
             -
,    (   -
     )   
    200,      
 20.       , 
           
 .

 , , ,   , -
   ,   
   (    -
 )       (- -
        
        -
 ).

     ^ -
      . 6.29.