1995 IEEE 802.3u, 100- Fast Ethernet. ( MAC LLC), CSMA/CD, . Ethernet Fast Ethernet . Fast Ethernet 2.1.
2.1 Fast Ethernet (PMA Physical Medium Attachment, , PMD - Physical Medium Dependet, )
10- 100- , 10 ( 100 Ethernet). (RTT) 2,6 , Fast Ethernet 205 .
Fast Ethernet - () ( ), 5 ( ) 3 ( ). . ( ) ( 2.2). ' (
-) .
2.2 Ethernet
Գ (Reconciliation Sublayer, RS) (Physical Layer Device), ' , (Media Independent Interface, MII).
г , (, MAC), AUI, MII.
(4B/5B 8B/6T), (NRZI MLT-3) , (, ).
, Fast Ethernet , 100 /, IEEE 802.3u 802.3. 100BASE-T4, 100BASE-TX 100BASE-FX ( 2.3). CSMA/CD, , 10 100 /, 10 / 100 /.
2.3 - Գ Fast Ethernet
100BaseFX 1300 . , . 㳿 FDDI 4B/5B NRZI. 412 , 2 . ( 32 .). 100BaseFX 10BaseFL, .
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100BaseTX (UTP Cat 5 STP Type 1). , ( ') 10- Ethernet. 100 . 4B/5B, MLT-3.
100Base-T4. 㳿, 4 (UTP Cat 3), ' (UTP Cat 5). PCS , , . 86, 33,3 /c 16 ( , 3 ). 100 . .
- .
100Base-T4 100 /.
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, .
86 2.67 .
20 25 .
(32.671.25=10) . Fast Ethernet 1.
1. Գ Fast Ethernet (IEEE 802.3u)
Գ | 100Base-FX | 100Base-TX | 100Base-T4 |
Duplex SC | RJ-45 | RJ-45 | |
UTP Cat. 5 | UTP at.3,4,5 | ||
4B/5B | 4B/5B | >8B/6T | |
NRZI | MLT-3 | NRZI | |
/ | 2 | 2 | 4 |
412 (mm) 2 (mm)* 100 (sm)* | 100 | 100 | |
: mm - , sm , * - . |
, 100BaseTX 100BaseT4, (auto-negotiation),
, . 5 ( ): 10Base, 10BaseT, 100BaseTX, 100BaseT4, 100BaseTX.
17- FLP (Fast Link Pulse), , . NLP ( 10BaseT ), 쳺, 10BaseT.
, , I ( 4B/5B, 8B/6T) II ( ). I 100BaseFX, 100BaseT, 100BaseT4, ,
, 140 bt. I. II 100BaseFX 100BaseTX, 100BaseT4. , , 92 bt (TX/FX) 67 bt (4). II 2. Fast Ethernet 205 , 100 , ( II) ' 5 [1].
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2.2.1 CSMA/CD (/)
- / , -, , , - .
. -, . , , ( ), (9.6 ), , ', .
, , , , , , . 泔 .
, . 糺 (collision). 糿 , , ( ). , , , (jam), 32 , ( ). ϳ (, ).
糿 ( 512 , 51,2 ). ʳ , 0..2n (1<=n<=10) 0..210 (10<n<=16). n . 16 ( 糿), MAC .[1]
DSL
, , ' . ' . . ( ) , . , , , . ' , , '. ; , , 56 / . DSL , . ' , . ', , . , x , 㳿 DSL. ADSL, RADSL, HDSL, SDSL, VDSL ADSL Lite (G-Lite). , , , . ADSL (Asymmetric DSL) , . 볺 , 볺 . ADSL , . , . ADSL 볺 1,5 8 / 640 / 1,54 / - . 24 AWG (American Wire Gauge, - 0,6 ) 18000 (5,4 ). , - 0,5 , 26 AWG. 15 000 (4,5 ). , 㳺 ADSL , , - splitter (, ).
RADSL (Rate adaptive ADSL - ADSL ) 㳿 , . .ADSL Lite, G.Lite, . 볺 . , '. 㳿 15 ITU (International Telecommunications Union - ̳ ) G.992.2 1998 . , , ANSI, ATM ADSL.HDSL (High Bit-Rate Digital Subscriber Line - DSL) 1,544 / 2,048 / . T1 E1. , ADSL, - 12 000 (3,6 ), ' , 볺 -. . ANSI HDSL II, HDSL , , , . SDSL (Single-Line DSL) , HDSL, 10 000 (3 ) HDSL II., VDSL (Very High Bit-Rate DSL) , 13 52 / 볺 1,5 2,3 / 1000 4500 (300-900 ). , ADSL, VDSL (). 㳿 DSL ( G.Lite), , . - , , . DMT , CAP . - CAP DMT - , , . г . CAP , . , 㳿, - . ( ). , . , , , . DMT ANSI T1.413 1,1 256 , , 4,3125 . 1 6 . 7 38. 볺 250 7-38, 218 - ( ). , , . QAM. , DMT , - . , / . CAP, .DSL, , - , 䳿 . , DSL , SONET ( , ). , ATM, IP, - . , , ADSL, . . 볺 ADSL- , , . , , , . ֳ . , 볺, ' , , ' . , ADSL - ' ' , . ADSL , .
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㳿 FDDI
FDDI , - .
, :
(DAS) 200 /;
(SAS) 100 /.
500, 100 , 2 , UTP 5 100 .
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FDDI (Fiber Distributed Data Interface, ) ANSI. 㳿 FDDI - ( ). 100 /. FDDI 100 . 2.5 . 1000. (primary). (secondary) . , . , FDDI ( 2.4).
2.4 FDDI:
; ,
: , , . , . , , . FDDI , - , , .
FDDI , Token Ring. : , . ϳ T_Opr. . , , . , (Token Rotation Time, TRT) . (TRT<T_Opr), ( ) , THT=T_Opr-TRT. (TRT>T_Opr), .
FDDI , ( ). FDDI Token Ring, .
FDDI :
MAC (Media Access Control), , , , ( OSI);
PHY (Physical) , ;
PMD (Physical Medium Dependent) , ' (PMD PHY OSI);
SMT (Station Management) , , /, , , ( ).
FDDI (MMF-PMD, 2 .), (SMF-PMD), 5 STP Type 1 (TP-PMD). FDDI 1300 . -SDDI CDDI (Copper Distributed Data Interface) TPDDI (Twisted Pair Distributed Data Interface). SDDI (STP). 100 . CDDI , . FDDI . 4B/5B. Գ NRZI, MLT-3.
2.5 .
2.6
2.7 FC-
FDDI , 4- 5- , 100 / 125 .
Token Ring, FDDI , . FDDI Token Ring. ( ) ( ).
FDDI 2.5. SD, FC, ED, FS Token Ring.
2.6, FC- 2.7. [1]
FDDI . , , FDDI. ³' - .
: - ;
- :
- ;
- ;
: .