( . ). -.
ISDN :
(Unrestricted digital). 64 /, 8 . . , .
(Sh). - 8 , 64 / . , , . .
(3.1 kHz Audio). 8 , 64 / 3 1 , .
3.2. .
.
ISDN :
3.1 (Telephony 3.1 kHz)
. 3,1 . (), -.
7 (Telephony 7 kHz)
3.1 , , 7 64 /.
. 4 (Telefax Grp. 4)
4, , , 10 , 300-400 . 3 4, .
64 / (Teletex 64 kbit/s)
, - . " ". , , 4, .
|
|
|
12 2,4 / 4. ISDN, 1.
(Videotex)
, .
ISDN . , . ( 2 ) 64 /.
(Videotelephony)
. -, 20% , 80% - . , . . .
. .
.
ISDN 3.1 .
3.1 3.1 .
, , , .
3.3. .
, , .
ISDN :
,
( );
,
;
;
;
;
;
;
;
- ;
- ;
|
|
|
,
;
;
,
,
;
;
;
,
-.
DSS1.
ISDN ISDN 1 (DSS1 - Digital Subscriber Signaling 1). ETSI: ETS 300 102, ETS 300 369, ETS 300 402, ETS 300 403, ETS 300 485, ETS 300 745. . DSS1 D- .
4.1. DSS1.
DSS1 .
ALERTING - , , .
CALL PROCEEDING - , , .
CONNECT - , . ANSWER .
CONNECT ACKNOWLEDGE - , . , - . , .
PROGRESS - .
SETUP - .
SETUP ACKNOWLEDGE - , .
RESUME - .
RESUME ACKNOWLEDGE - .
RESUME REJECT - .
SUSPEND - .
SUSPEND ACKNOWLEDGE - .
SUSPEND REJECT - .
USER INFORMATION - . . , , "User-To-User Signalling".
DISCONNECT - , , .
RELEASE - , , RELEASE COMPLETE.
|
|
|
RELEASE COMPLETE - RELEASE , .
CONGESTION CONTROL - USER INFORMATION.
INFORMATION - (, ) .
NOTIFY - , .
STATUS - STATUS ENQUIRY .
STATUS ENQUIRY - STATUS 3 . STATUS STATUS ENQUIRY .
. , SETUP .
Sending complete - , , SETUP.
Bearer capability - (bearer service) .
Channel identification - . , " ".
Facility - .
Progress indicator - , ISDN.
Network specific facilities - .
Display - , - .
Calling party number - .
Calling party subaddress - , . , SETUP.
Called party number -
Called party subaddress - , . , SETUP.
Transit network selection - .
Low layer compatibility - , , SETUP
High layer compatibility - (teleservice) - . , . , SETUP.
|
|
|
User - user - , - . , SETUP.
