556     6   _______________________________

  MBS.       
.        PCR,  -
    ,      , 
 MBS.     Burst Tolerance,   -
  .         
 PCR, SCR  MBS.

  PCR     ,   ,
        CLP=1.

   rtVBR       QoS,
     CBR,    nrtVBR  -
  .      
 VBR       CLR,
      ,   
     .

     QoS     
       Generic Cell Rate
Algorithm,        
,  PCR, CDV, SCR, , CTD  CDV.    -
   ,    frame relay.

  ,       -
  ,     -
,    . ,  
        
      ,   
 -  .

   CBR    VBR,  UBR    -
 ,    .  UBR 
     - .  -
      , 
UBR        
,        .

   UBR    
        . 
  ,  UBR    . -
       ,  
   ,   .     -
 UBR       QoS,   
   .

 ABR   UBR   
 ,       
      . ABR     
 ,       -
    ,      
       ,   
    .

    CBR  VBR,     ABR
    PCR.    
         .