6.3.              511

      1920 /.    -
   PRI        D,  
     ,     D,  -
  24  31.

        .   
        2,048 
1,544 /.      3HO+D  
  5HO+D  .   HI  , -
      (1,536 /)   
   HI 2 (1,920 /)    D   -
.

  PRI    DS-1   1  1.
  PRI    1.431.

     ISDN

     ISDN   -
   ,  CCITT (. 6.17). -
    ,      
   (reference points)    -
  .

	;	1			NT2			NT1		
				4- 100-		 , 				  ( 2-  5,5 
					  -1000					
2										
	;									
										

. 6.17.    ISDN

   NT1 (Network Termination 1)  -
   (Digital Suscriber Line, DSL)  , 
    ISDN.  NT1  -
   CSU,        -
     CSU,   
  ISDN.   U    -
 NT1  .  NT1     (
    ),     -
.      NT1   , -
   (,   
ISDN)     NT1.    
  NT1   , -
         -
 NT1.

     BRI,   
   2-  (    
 ).      
     2B1Q  --