X.25 , LAP-B .
: . . X.25 . ( ; ; , )
LAP-B LAP-M, -. 8 1- 128 2 .
X.21 - () () .
X.25 14 . , . X.25 . .
Q 1
0
D
mod :
10 128
01 8
LGN
LCN -
VCI
TYPE
B 0
1
DA
SA
8 .
, ( : 16, 32, 64, 128, 256, 512, 1024 ).
. , . VCI . , . ( VCI)
| k1 | k2 | ||
| DA | SA | ||
31381120 31381140 1 k1. , VCI = 4.
1k1:
| VCI-IN | VCI-out | ||
| * - |
3k1:
| VCI-IN | VCI-out | ||
| * - |
1k2:
| VCI-IN | VCI-out | ||
| * - |
4k2
| VCI-IN | VCI-out | ||
| * - |
|
|
|
. SA DA. 1 1- . 11 3 . 3- 1- k2. 4 . .
. 8. (MNP 5, MNP 7, V42 bis)
2
1) ( )
2) ( )
,
1- :
200
+
84
300
:
2- :
279
, .
1)
2)
3) abcdefgh 2 . 1, 0
. MNP 5
MNP5
