Ethernet Technology
Ethernet Technology
Ethernet Technology
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Comparison of various <strong>Ethernet</strong> Specifications<br />
<br />
<br />
<br />
Medium<br />
<br />
Encoding<br />
<br />
Data rate<br />
<br />
(MSL)<br />
<br />
(MES)<br />
<br />
<br />
(NPS)<br />
<br />
(DBN)<br />
Topology<br />
10BASE5 10BASE 2 1BASE5* 10BASET* 10BROAD36 10BaseFP<br />
<br />
50 50 <br />
<br />
Manchester<br />
10 Mbps<br />
500 <br />
2500 925 2500 <br />
100<br />
2.5 <br />
<br />
Bus<br />
<br />
Manchester<br />
10 Mbps<br />
185 <br />
30<br />
0.5 <br />
Bus<br />
<br />
<br />
<br />
Manchester<br />
<br />
<br />
<br />
Manchester<br />
1 Mbps 10 Mbps<br />
500 <br />
2*<br />
depends on<br />
hub’s ports<br />
1000m *<br />
Star<br />
100 <br />
500 <br />
2*<br />
depends on<br />
hub’s ports<br />
200m*<br />
Star<br />
<br />
75 <br />
<br />
DPSK<br />
10 Mbps<br />
1800 <br />
3600 <br />
Bus/Tree<br />
850-nm FO<br />
pair<br />
<br />
Manchester<br />
10Mbps<br />
500 <br />
1000 <br />
2*<br />
up to 33/coupler<br />
1000m *<br />
Star<br />
• Recall<br />
Throughput - Performance of CSMA/CD<br />
B transmits<br />
. . .<br />
. . .<br />
• Consider time on the medium to be organized into slots<br />
(slot time = the max time (2), from the start of transmission, required to detected a collision)<br />
2<br />
Spacing doesn’t exist<br />
. . .<br />
. . .<br />
(either a collision or no<br />
transmission in each slot)<br />
Avg.=m<br />
* “ 1 ” if per-media segment <strong>Ethernet</strong> <strong>Technology</strong> 34<br />
<strong>Ethernet</strong> <strong>Technology</strong> 33<br />
TH<br />
max<br />
U <br />
R<br />
<br />
a(1 A)<br />
<br />
A<br />
1<br />
(<br />
max<br />
0.368 .)<br />
(U)<br />
Max distance<br />
Data rate<br />
propagation time d / v dR <br />
L<br />
Let ; m <br />
R<br />
, <br />
transmission time L/<br />
R vL m<br />
Signal propagation velocity<br />
Average frame length<br />
1 1<br />
1 2 13.44a<br />
A e as N<br />
2<br />
51.2s (512 bit time)<br />
(N)<br />
High-load<br />
<strong>Ethernet</strong> <strong>Technology</strong> 35<br />
d<br />
v<br />
comparison<br />
• Frame in <strong>Ethernet</strong>s<br />
Maximum Throughput<br />
(w/o collision)<br />
56 8 48 48 16 12,000 max 32 96 <br />
Preamble SFD DA SA L/T LLC PAD FCS<br />
* Sometimes, whole thing excluding IPG<br />
a packet in Layer1<br />
Frame = Payload<br />
Frame Size Data Payload Max Throughput Efficiency<br />
(bytes) (bytes) Frames/sec Bytes/sec (%)<br />
1518 1500 812.744* 1219116 97.53<br />
1280 1262 961.538 1213461 97.08<br />
1024 1006 1197.318 1204502 96.36<br />
512 494 2349.624 1160714 92.86<br />
256* 238 4528.986 1077899 86.23*<br />
128 110 8445.946 929054 74.32<br />
64 46 14880.952* 684524 54.76<br />
64 32 14880.952* 476191 38.10<br />
64 24 14880.952* 357143 28.57<br />
64 16 14880.952* 238095 19.05<br />
64 8 14880.952* 119048 9.52<br />
64 3 14880.952* 44643 3.57<br />
+ 144 bits<br />
T = DP x MF<br />
How efficiently the LAN is being<br />
<strong>Ethernet</strong> <strong>Technology</strong><br />
used over a given period of time ?<br />
36<br />
IPG<br />
812.744 = 10x10 6 /[56+8+ . . . +(1500 x 8) +32+96] * wire-speed traffic<br />
T/E<br />
FS
Change language