4.3.              291

 .   ,      
    ,   , -
, .        -
    ,      
    .

   .    
       
    .   
  ,   ,   -
  ,     .

   .    -
        .
     .     -
  ,       
 .      .

     :   .
     , -
        .

     

       ,
     ,      -
.       , 
       .  -
          
      .    
      
        -
, ,   ,  .

,          
   (bridge) /  (switch, switching hub).  
    90-   ,    -
     .    -
   ,      .

         .  
         .  
    :   
(transparent bridge),    IEEE 802. ID,    
   (source routing bridge)  IBM  
Token Ring.         -
,      .     
      Ethernet,   -
      IEEE 802. ID,    -
       .    
   . ,    -
 Token Ring,    Source Routing,   
IBM.