6.2.            493

          ,
         -
 ,      ,  
 ,      -
 .       .

     :   -
 ,  ,  , -
   .

   .    -
         -
,    ,    
.  ,   ,  -
        -
     .

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

,       , -
    (Link Control Protocol, LCP). , -
      ,   
    , .  -
   (Network Control Protocol, NCP).   --
       .

    -   -
.         
(Password Authentication Protocol),       
,   CHAP (Challenge Handshake Authentication Protocol),  -
         
.        -
.        .

      
        
 -.     SLIP,    
IP-,  LAP-B,      .25,  -
     ,  IP, Novell IPX, AppleTalk,
DECnet, XNS, Banyan VINES  OSI,      -
 .        -
   NCP.   ,
-,   ,      
  ,  -,    -
 .       IP 
IP- , IP-  DNS,    IP-
  . .     -