Ethernet. 1972 ( Xerox). , 1980 , DEC Intel ( DIX ). 1985 Ethernet , : 802 IEEE (Institute of Electrical and Electronic Engineers) ECMA (European Computer Manufacturers Association).
IEEE 802.3 (- "eight oh two dot three"). , CSMA/CD. , . IEEE 802.3 , . IEEE 802.3 Ethernet.
IEEE 802.3:
- ;
- ;
- 10 /;
- 5 ;
- 1024;
- 500 ;
- 100;
- CSMA/CD;
- , ().
, IEEE 802.3 Ethernet , .
Ethernet ( 90% ), . , , , , Ethernet, .
Ethernet 50- ( ). ( 90- ) Ethernet, . . IEEE 802.3 . 1995 Ethernet, 100 / ( Fast Ethernet, IEEE 802.3u), . 1997 1000 / (Gigabit Ethernet, IEEE 802.3z).
. , () . (. 7.1).
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. 7.1. Ethernet
( ) . , ( ) . (). , , ( ).
( ) 6,5 , 3,5 .
Fast Ethernet , . Fast Ethernet . 10 . 10 (5,12 51,2 Ethernet).
Ethernet .
Ethernet CSMA/CD, . , . 7.2. ( )
. 7.2. Ethernet
Ethernet ( ) 512 51,2 ( ). , .
Ethernet :
- 8 , 10101010, 10101011. IEEE 802.3 (SFD Start of Frame Delimiter) .
- () () 6 , " " 4. .
- (L/T Length/Type) . . , 1500, . 1500, . .
- 46 1500 . 46 , . IEEE 802.3, (pad data ), , ( 46 ).
- (FCS Frame Check Sequence) 32- (CRC) .
, ( ) 64 (512 ). 512 (51,2 Ethernet 5,12 Fast Ethernet). , , . 1518 (12144 , 1214,4 Ethernet, 121,44 Fast Ethernet). .
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. , (101010...10) , (. 2.6.3), . , () , - . (11) 101010...10 ( ). ( ).
Ethernet, 10 /, , :
- 10BASE5 ( );
- 10BASE2 ( );
- 10BASE-T ( );
- 10BASE-FL ( ).
: "10" 10 /, BASE ( ), : "5" 500 , "2" 200 (, 185 ) : "" ( "twisted-pair"), "F" ( " fiber optic ").
Ethernet, 100 / (Fast Ethernet) , :
- 100BASE-T4 ( );
- 100BASE-TX ( );
- 100BASE-FX ( ).
"100" 100 /, "" , "F" . 100BASE-TX 100BASE-FX 100BASE-X, 100BASE-T4 100BASE-TX 100BASE-T.
Ethernet, CSMA/CD (CRC) . , Ethernet , , . , , , Ethernet , Ethernet.
Ethernet . . ( Fast Ethernet Gigabit Ethernet) . CSMA/CD ( ) . , Ethernet.
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Token-Ring
Token-Ring ( ) IBM 1985 ( 1980 ). , IBM. , IBM, , , . , Token-Ring IEEE 802.5 ( Token-Ring IEEE 802.5 ). Ethernet.
Token-Ring Ethernet. Ethernet , Token-Ring . 10 .
IBM : . , , 3OM, Novell, Western Digital, Proteon . , , IBM PC Network NetBIOS. PC Network NetBIOS , Token-Ring NetBIOS . .
Token-Ring , . , () , (MSAU MAU Multistation Access Unit). - (. 7.3). - , , .
. 7.3. - Token-Ring
(MAU) , , .. (. 7.4). .
. 7.4. Token-Ring (MAU)
(TCU Trunk Coupling Unit), , . , TCU . TCU ( "" ), , . ( . 7.4). "" , .
(. 7.5).
. 7.5. Token-Ring (8228 MAU)
(1...8) () (Adapter cable) . : RI (Ring In) RO (Ring Out) (Path cable). .
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, MAU. , ( , Ethernet). , .
( .7.4), , . , . , - .
, . , Token-Ring , .
, (. 7.6).
. 7.6. MAU
() , . , (. 7.7). , .
(), , (. 7.8). , . , , .
, (cluster), . , , , 16 ( ).
. 7.7.
. 7.8.
IBM Token-Ring , (UTP), (STP), , FDDI.
Token-Ring:
- IBM 8228 MAU 12;
- 96;
- 45 ;
- 45 ;
- , 120 ;
- 4 / 16 /.
. , . , (STP) 260 ( 96), 100 ( 45), 33, , 200 . .
Token-Ring (, ). , . .
Token-Ring RJ-45 ( ), MIC DB9P. ( "" ).
Token-Ring Ethernet , . , Token-Ring 100 / (High Speed Token-Ring, HSTR) 1000 / (Gigabit Token-Ring). , Token-Ring ( IBM, Olicom, Madge), , Ethernet.
Ethernet Token-Ring , , Token-Ring .
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Ethernet Token-Ring ( 3040%) . , , , .
Token-Ring , , (. . 7.8). , , , ( ).
Token-Ring 10 . 260 260 x 10 = 2,6 . 260 (, , ). . Token-Ring.
( ) :
- ;
- ( , );
- , .
, , .
( ). , .
:
- ;
- ( 7 ) (AMP Active Monitor Present);
- , ;
- .
, , , , . , , ( ), , . 24 4 / 32 16 /.
, . - , , (, ) . , , ( ) MAC-. MAC- . , . , MAC-. , MAC- , ( MAC-). .
Token-Ring , (. 7.9): (SD Start Delimiter), (AC Access Control) (ED End Delimiter). , , .
, . , .
. 7.9. Token-Ring
SD (. 7.10). , J, . , , . , . J K .
. 7.10. (SD) (ED)
ED ( J K), . , , , :
- I (Intermediate) (1 , 0 ).
- E (Error) (0 , 1 ).
(AC Access Control) (. 7.11): ( ), , ( ).
. 7.11.
() ( 0 7, 7 , 0 ). , ( ) .
, ( , ). , , , .
() , . ( ) , , . . , .
, . .
() Token-Ring . 7.12. , , , , .
. 7.12. () Token-Ring ( )
().
- (SD) , , .
- (AC) , .
- (FC Frame Control) ().
- MAC- , 4.
- (Data) ( ) ( ).
- (FCS Frame Check Sequence) 32- (CRC).
- (ED), , . , , , (. . 7.10).
- (FS Frame Status) , : ( , ) . , .
, Ethernet . 16 / 100 / 18 , . 4 / Token-Ring , Ethernet (10 /). Token-Ring ( 3040%), CSMA/CD .
, , . . . .
Token-Ring , (Abort). . (SD) (ED) .
, Token-Ring (16 / ) (ETR Early Token Release). , .
ETR , , , . , , . , . , .
( , "" ). ( TCU, . 7.4). , "" . , . . , . . .
( ). , . () , , .
Token-Ring . , . , .
, (. 7.13) - , (. 7.14).
. 7.13.
. 7.14.
Arcnet
Arcnet ( ARCnet Attached Resource Computer Net, ) . Datapoint Corporation 1977 . , . , Arcnet ( 1980 1990 ..) , Ethernet. (, Datapoint, Standard Microsystems, Xircom .) . Arcnet .
Arcnet Ethernet , , , . (2,5 /), .
Arcnet , , . , , , .
93 , , RG-62A/U. ( ) . , Arcnet.
Arcnet (Arcnet -BUS), (Arcnet -STAR). (). ( Ethernet). (). : , , .
:
- ( ). 4 64. ().
- ( ). 4. . / .
.
:
- (Bus), :
- (Star), .
, 93- . . . 93- . , , .
, Arcnet (. 7.15).
. 7.15. Arcnet (B , S )
Arcnet .
- , .
- 6 .
- 30 .
- 600 .
- 30 .
- 600 .
- 255.
- 8.
- 1 .
- 300 .
- 2,5 /.
, 30 . 5 11 .
Arcnet ( ), Token-Ring. , IEEE 802.4. :
1. , , .
2. , - (, ).
3. , , ( ).
4. , - .
5. , .
6. , , . .
, , . .
, Token-Ring, Arcnet . , Arcnet ( Ethernet). 840 . , .
. () .
840 , ( ). ( ) .
Arcnet 0,5 . 8- 16- (CRC). .
Arcnet , ( 255, , 256- ). . , , . 8- 255, .
Arcnet. Arcnet, 20 /, .