.
, () .
xDSL . .
ISDN .
() .
, . , . ISDN . ISDN . . , . .
CPE (Customer Premises Equipment) (TE- Terminal Equipment) (NT- Network Terminal).
ISDN
. S (short passive S bus), .
ISDN CPE (Customer Premises Equipment), ISDN, . : , () , , , Frame Relay.
18. ISDN. . . .
ISDN , .
: , D (1).
1 - ISDN
2B+D | BRI | D | |
30B+D | 23B+D | PRI | D |
5H0+D | 3H0+D | PRI | D |
H12+D | H11+D | PRI | D |
( , ) 64 / . TDM (TDM - Time Division Multiplexing). , ISDN .
|
|
D , 16 64 /. , , D. . , D .
384 / (), 1536 / (11) 1920 / (12). , , .
ISDN . ISDN (Basic Rate Interface, BRI) (Primay Rate Interface, PRI).
ISDN BRI 64 / ( ) 16(64) / ( D). . BRI 128 /, 144(192) /.
TDM, , .
BRI , 48 . 2 , 4 D. 250 , 64 / 64 / D. , . BRI 2 + D, + D D.
PRI ISDN . PRI 30 + D, 23 + D. D 64 /. , . 2,048 / 1,544 / PRI .
PRI , 20 + D. 1920 /. PRI D, , D, 24 31.
|
|
. 2,048 1,544 /.
ISDN
ISDN.
ISDN :
1). ISDN-.
D-
1 (DSS1).
:
2). SSN7.
ISDN-.
ISDN , , U, S, , R.
U, U, " ", (Switch NT)
2 (adapter) R.
S . , , S/T. S/T , NT1 NT2, S NT2. NT1 ISDN. NT2 ISDN, ISDN.
19. ISDN. DSS-1 QSIG.
Signaling of DSS - 1 . QSIG ISDN. ISDN Q.
CCS - 7.
Structure of cycle LAPD (Link - Access Protocol on the D channel) with the address field is shown on a figure 3.
20. BISDN. , .
BISDN.
BISDN (Broadband Integrated Service Digital Network) ISDN. ISDN, / / , BISDN - / .
ISDN : . TDM (Time Division Multiplexing). , . BISDN , . :
.