, PHY FX PHY TX, (full-duplex mode). CSMA/CD - Tx Rx.
' ' .
100Base-TX 100Base-FX 200 /.
100Base-T IEEE . , , . ' .
, , Ethernet, , .
thrnt . , , (XOFF). (XON).
Fast Ethernet I II
Fast Ethernet, Ethernet, - ' - () .
Fast Ethernet :
, ' DTE c DTE;
, ' DTE ;
;
, ' .
DTE-DTE.
DTE (Data Terminal Equipment) - : , , , . DTE. Fast Ethernet DTE , 㳿.
IEEE 802.3u DTE-DTE:
2.1 DTE-DTE.
100Base-TX | Category 5 UTP | 100 |
100Base-FX | - 62,5/125 | 412 () 2 ( ) |
100Base-T4 | Category 3,4 5 UTP | 100 |
|
|
, ' ' .
Fast Ethernet .
I : 100Base-TX/FX 100Base-T4.
II - 100Base-TX/FX 100Base-T4.
. (bt) [1].
10 Ethernet .
100 Ethernet .
1000 Ethernet .
I. ' , (70 bt).
: 46bt TX/FX 33,5bt 4. II - 2, ' 5 .
Fast Ethernet . -, - - . -, , , , . .
( 2) I.
2.2 1.
ҳ (TX) | 200 | 100 |
ҳ (FX) | 272 | 136 |
ʳ c | 260 | 160 (FX) 100 (TX) |
ʳ | 272 | 100 (TX) 136 (FX) |
3. ֲ ί Ҳ ϒί Ʋ
3.1 Ethernet
, 4 Ethernet, , :
1. ʳ 1024;
2. ;
3. (Path Delay Value, PDV) 575 ;
4. IPG (Path Variability Value, PVV) 49 . 96 , 96 49 = 47 .
, , 2500 .
|
|
.3.1 Ethernet, .
PDV. , , () ( 3.1).
.3.1 Ethernet .
3.1. PDV
, bt | , bt | , bt | 1, bt | , | |
10 Base-5 | 11,8 | 46,5 | 169,5 | 0,0866 | |
10 Base-2 | 11,8 | 46,5 | 169,5 | 0,1026 | |
10 Base-T | 15,3 | 42,0 | 165,0 | 0,113 | |
10 Base-FB | 24,0 | 0,1 | |||
10 Base-FL | 12,3 | 33,5 | 156,5 | 0,1 | |
FOIRL | 7,8 | 29,0 | 152,0 | 0,1 | |
AUI(>2 ) | 0,1026 | 2+48 |
˳ , . . . , , , . . . (), . , , . , , . , ( 1 ), . PDV 575 bt.
, : , . PDV.
.3.1:
˳ 1: 15,3 + 100 * 0,113 = 26,6 bt.
2: 33,5 + 1000 * 0,1 = 133,5 bt.
3: 24 + 500 * 0,1= 74,0 bt.
4: 24 + 500 * 0,1= 74,0 bt.
5: 24 + 600 * 0,1= 84,0 bt.
6: 165 + 100 * 0,113 = 176,3 bt.
, PDV = 568,4bt < 575bt. .
PVV. PVV. PVV Ethernet 3.2 :
3.2.
, bt | , bt | |
10 Base-5 10 Base-2 | ||
10 Base-FB | ||
10 Base-FL | 10. 5 | |
10 Base-T | 10. 5 | |
100 Base-TX(I) | _ | |
100Base-TX(II) |
PVV :
˳ 1: 10,5 bt.
2: 8 bt.
3: 2 bt.
4: 2 bt.
5: 2 bt.
PVV = 24,5bt < 49bt. .
|
|
, , .3.1, Ethernet , , .
3.2 FastEthernet
, Fast Ethernet, , , , :
1. ʳ 1024.
2. (Path Delay Value, PDV), 512 .
3. (Interpacket Gap Shrinkage), , , 96 .
: 10 .
3.3. , .
3.3 , .
bt 1 . | ||
UTP Cat 3 | 1,14 | 114 bt (100 ) |
UTP Cat 4 | 1,14 | 114 bt (100 ) |
UTP Cat 5 | 1,112 | 111,2 bt (100 ) |
STP | 1,112 | 111,2 bt (100 ) |
1,0 | 412 bt (412 ) |
, ( ), 3.4.
3.4 ,
TX/FX | 100 bt |
T4 | 138 bt |
TX/FX T4 | 127 bt |
, , , 140 bt, , . 512, . 0-5 bt ( 4 bt).
3.2 ᒺ.
80 ., 90 .
ǒ . 5 (UTP5).
. . ̳ . () 5 , . , , , 䒺 .
, , . , Internet.
. 3.2 Fast Ethernet
. 3.3
PDV. , , () ( 3.1).
(.3.2).
|
|
, II, 33,5*2=67bt
,
UTP Cat 5 1,112 bt
1,0 bt
T4 138 bt
PDV (.3.3).
:
2 T4 = 138bt
90*1.112=100,08 bt
90*1.112=100,08 bt
67 bt
PDV=67+100,08+100,08+138=405,16 bt
PDV = 405,16 bt
10% PDV. PDV = 445,68bt. 512 bt, .
PVV. (.3.3). ( ), 33,5bt, , . , .
PVV = 33,5
4. ί
. :
1.
, :
ʳ | ʳ | ʳ | ||
10Base-T 10Base-2 | 12 12 |
, , 10Base-T 10Base-2.
2.
, Ethernet ( ).
3.
, , () . 璺 . 璺 , 璺 . . , ( ) . . 璺 .4.1- 4.2. :
, .
.
, , 璺 , .
.4.1.
.4.2. 璺 .
(), . , 璺 , 䒺 .
.4.2 . . ³ , , , , , .
4.