Bellcore - Synchronous Optical NETs, SONET. 1984 . T1 ANSI. (ETSI) CCITT ANSI , . , ( 1 - , 1 - ) - , PDH, .
Synchronous Digital Hierarchy, SDH ( G.707-G.709), SONET , SDH SONET PDH - , . SDH SONET , , SONET/ SDH . SDH.
SONET/SDH, SONET/SDH, . 6.3.
6.3. SONET/SDH
SDH (, , ) : STM-n - Synchronous Transport Module level n. SONET : STS-n - Synchronous Transport Signal level n, , -n - Optical Carrier level n, - . STS .
, SONET 51,84 /, SDH - 155,52 /, SONET. 155,52 /, SDH PDH - SDH DS-4, 139,264 /. SONET/ SDH STS-1. 155,52 / DS-4 SONET/SDH.
SONET SDH, , , STS-3/STM-1. , , :
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, (add) (drop) , ;
;
;
.
SONET/SDH . 6.7.
. 6.7. SONET/SDH
, SONET/ SDH.
(Terminal, ), (Service Adapter, SA), PDH ( 1/1 /) STS-n. ( STS-n SONET/SDH.)
(Muliplexers) STS-n STS-m.
- (Add-Drop Multiplexers) STS-n, , , , .
- (Digital Cross-Connect, DCC), (), STS-n ( . 6.7 ). - , - , , . - SONET/SDH.
, , . , , , -, -.
4- .
, (photonic), . NRZ ( ).
(section) . - , SONET/SDH , . . , 64 /, 192 /. 11110110 00101000, . : STS-1, STS-2 . . .
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(line) . STS-n , . , . - - - , .
(path - ) . () - . , , 1, STS-n/STM-m.
. 6.7, , . , , , STS-n . - , . , , -, , .
STS-1 . 6.8. SONET/SDH , n m . , (Virtual Container, VC - SDH) (Virtual Tributaries, VT - SONET). - , , , SONET/SDH 51,84 / (, 1 1,544 /).
. 6.8. STS-1
STS-1 9 90 , 810 . - , . . 3 . 3 9 , . 6 , , . SONET/SDH, , , , . , .
. , 1/1. , (pointers).
SONET/SDH. .
. , . SONET/SDH , . ( SPE - Synchronous Payload Environment) . SPE HI, . , , . STS-1. , . 6.9.
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. 6.9.
STS-n. 1/1 / STS-n. , HI, . 4, . , 24 1, STS-1. .
, STS-n , , .
, . 1 1,544 /, 1,728 /.
SONET/SDH , STS-n. , . SONET/SDH , STS-n. , , .
SONET/SDH . - Automatic Protection Switching, APS. . 1:1. ( ) . , 1:n, n .
1:1 , . , . 1:1 , FDDI (. 6.10), . , , FDDI, .
. 6.10. SONET/SDH
1:1 , , - , .
, SONET/SDH . , -, . SDH, .