1. , .
2. ( 4) .
4
.
1. , (Signal Unit - SU). () , , , , , .
:
- (Message Signal Unit - MSU), , SCCP;
- (Link Status Signal Unit - LSSU), ;
- (Fill In Signal Unit - FISU), MSU LSSU.
2. MSU.
ITU-T Q.703 4. MSU , . MSU . , .
, 8- . . : 01111110.
, MSU , MSU, . .
4-
BSN, - BIB, FSN - F1B , .
LI , , , 0 63. 2 LI , - MSU.
SIO . , SIO , ISUP SCCP. :
|
|
|
00 -
01 -
10 -
11 - .
FSN - , . BSN - . - 0 127.
SIF 272 , . 63.
1 16- , .. 1 0 . , .
. , , . MSU .
5
DSS1
1. DSS-1 .
2. ( 5) DSS-1.
3. DSS-1.
5
.
1. ITU-T 1 (DSS-1 Digital Subscriber Signaling 1) ISDN D . (ITU-T) D :
- 16 /, ;
- 64 /, ( 30) .
DSS-1 ( OSI) .
(1 , ) DSS-1 D, , , , 2 3 D. 1 :
- S B D;
- ;
- .
D- (2 , ), LAPD (link access protocol for D channels), D NT. 2 , 2 D. , 2 , .
|
|
|
D- (3 , ) , , . 3 , 2
2. 1 ( ) I.430. 1 192 / - 64 / D- 16 /. - 48 / - , , NT. 48 , - 250 . S . , , , INFO.
3. , , .
3 DSS1 6.
6
| Alerting | ||
| Call Proceeding | ||
| Connect | () | |
| Connect Acknowledge | ||
| Progress | ||
| Setup | ||
| Setup Acknowledge | ||
| Disconnect | ||
| Release | ||
| Release Complete | ||
| Restart | ||
| Restart Acknowledge | ||
| Resume | ||
| Resume Acknowledge | ||
| Resume Reject | ||
| Suspend | ||
| Suspend Acknowledge | ||
| Suspend Reject | ||
| User Information | ||
| Congestion Control | ||
| Facility | ||
| Information | ||
| Status | ||
| Status Enquiry | ||
| Notify |
6
