.7-7 ISDN, 4- : 3- 7- OSI, 4- - 4-7 .
| 4-7 | ||
| Q.931 | ||
| LAPD (Q.921) | ||
| BRI (I.430) | PRI (I.431) | |
.7-7. ISDN
ISDN, OSI ISDN ( ), . ITU-T:
( BRI, PRI - ITU-T I.430,1.431,1.432);
( ): LAPD - ITU-T I.441 (Q.921), Q.922;
(3) - . ITU-T 1.451 (Q.931), I.452 (Q.932), 1.453 (Q.933).
, BRI
ISDN BRI
BRI .. 6 (48 , 250 ). .. (-, -). 192 / ( , . ). - : NT - , NT - (.7-8).
.7-8. ISDN, NT () NT ()
, NT, 4 8 : 21 2 4 -. 9- L, . 12 , , , .7-1 ( 4 D-):
7-1
| 1-2 | F L |
| 3-11 | 1 (1- ) L |
| 12-13 | 1- D L |
| 14-15 | F L |
| 16-24 | 2 (1- ) L |
| 25-26 | 2- D L |
| 27-35 | 1 (2- ) L |
| 36-37 | 3- D L |
| 38-46 | 2 (2- ) L |
| 47-48 | 4- D L |
, NT , - (), 4- D-, . - D-. L .
ISDN, NT , .7-2.
7-2
| 1-2 | F L |
| 3-10 | 1 (1- ) |
| - 1- D | |
| 1- D | |
| , | |
| F | |
| N- | |
| 16-23 | 2 (1- ) |
| - 2- D | |
| 2- D | |
| () | |
| 27-34 | 1 (2- ) |
| - 3- D | |
| 3- D | |
| S 0 | |
| 38-45 | 2 (2- ) |
| - 4- D | |
| 4- D | |
| L |
|
|
|
ISDN PRI .7-1,.
