

                                   TOKEN RING





         Token Ring    IBM  1982 .  
 1985 .   IEEE (Institute for Electrical and Electronic Engeneers)  
 802.5.
     Token Ring     IBM   
 (LAN),      LAN  Ethernet/IEEE 802.3.
      Token Ring      - 4 /  16 
/.      802.5,     
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    Token Ring 16 /      
  ,   "  " 
(Early Token Release).         
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  80 %  .      
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     ,   Token Ring  
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         .



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     SOLICIT_SUCCESSOR  ,   
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 ,   RESOLVE_CONTENTION.   - 
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 ISU (Information Symbol Unit)    


 

  Token Ring    :
Data/Command Frame ( /), Token (), Abort ( 
).


   Token Ring

    ARCNet     . 
 ARCNet    Token Bus ( )
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       .

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.


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Token ring  FDDI

 Fiber Distributed Data Interface (FDDI) -   
 ,        
 .

FDDI        Token Ring  
 .    Token Ring FDDI    
-"".    FDDI  Token Ring  
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   .
    FDDI        
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 FDDI    100 /

    FDDI     Token 
Ring:

          
        .  
   ,  "   
" - TTRT (Target Token Rotation Time).



 TTRT        
 -    TTRT,        
  .       
          
     T_Opr,      
    .  TTRT  
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.
       
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 1L00 0011,       (DA = 
SA),      4-    
   T_Req.
 -         
,     Claim Token     
   TTRT,     T_Req   
TTRT.      Claim  .   
,   Claim Token,    Claim Token. 
         
 Ring_Operational   False,     
      .     
    Claim.
        
    TRT (Token Rotation Timer),  
          .  
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,         
  ,    . (  
 FDDI       ).
 TRT        
 Claim Token.       
    ,   165 .  
 TRT        -  
  .     Claim Token 
  Beacon  Trace,      
          .
    Claim Token     
    Claim   T_Req,    
 TTRT.      T_Opr,   
TTRT.    ,    9.
            
    : 72 , 37 , 51   65 . 
,   Claim   ,    
T_Req,      TTRT  .



        ,  
 (  T_Req < TTRT),      
  Claim      Claim,   
,       .   
    T_Opr   T_Req,   
    Claim.       
T_Req ,    TTRT,     .
,     ,   ,  
   ,  ,  ,   ,  
  .

          FDDI  
  39.5  1986 - 1988 ,     
  -  , ,   
,   .
        
       ,  FDDI  
   ,    
    ,     
    .




           .
        -     
 ,    -,  .
 -  ,      
:
 ,   .     ,  
    802.3    .

