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“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Local Area Networks
Gerd Keiser
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Chapter Four
LAN Access Techniques
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
General concept of a simple queuing modelFigure 4.1
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Vulnerable period in the pure ALOHA schemeFigure 4.2
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Throughput versus offered load for pure and slotted ALOHAFigure 4.3
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Transmission attempts and random retransmission delays for colliding packets in slotted ALOHAFigure 4.4
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Successful and unsuccessful transmission attempts for nonpersistent CSMAFigure 4.5
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Throughput S as a function of the offered load G Figure 4.6
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Packet arrivals in slotted nonpersistent CSMAFigure 4.7
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Flow diagram for the CSMA/CD protocolFigure 4.8
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Performance comparisonsFigure 4.9
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Throughput as a function of G for 1-persistent CSMA/CDFigure 4.10
Reprinted with permission from Takagi and Kleinrock,17 © 1987, IEEE
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Examples of three types of polling schemesFigure 4.11
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Use of a central LAN switch in a star network architectureFigure 4.12
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
LAN-to-LAN and LAN-to-MAN/WAN switchesFigure 4.13
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
The basic concept of a LAN switchFigure 4.14
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Equilibrium throughput curve in slotted ALOHAFigure 4.15
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Equilibrium contours for slotted ALOHAFigure 4.16
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Example of a channel load lineFigure 4.17
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Example of a globally stable, lightly loaded systemFigure 4.18
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Bistable system: 2 locally stable & 1 unstable equilibrium pointsFigure 4.19
“Local Area Networks” - Gerd Keiser Copyright © 2003 - The McGraw-Hill Companies srl
Behavior of systems which are (a) stable but overloaded (b) unstable with infinite usersFigure 4.20