Ch03

McGraw-Hill ©The McGraw-Hill Companies, Inc., 2000

Chapter 3

Underlying Technologies


CONTENTSCONTENTS• LANS• POINT-TO-POINT WANS• SWITCHED WANS• CONNECTING DEVICES


Figure 3-1

Internet model


LOCAL AREA NETWORKS

(LANS)

3.13.1


Figure 3-2

CSMA/CD


Minimum frame length/Transmission rate Minimum frame length/Transmission rate is proportional to is proportional to

Collision domain / Collision domain / Propagation speedPropagation speed


Figure 3-3

Ethernet layers


Figure 3-4

Ethernet frame


Figure 3-5:a

Ethernet implementation


Figure 3-5:b



Figure 3-5:c



Figure 3-5:d Ethernet implementation


Figure 3-6:a

Fast Ethernet implementation


Figure 3-6:b



Figure 3-6:c



Figure 3-7:a

Gigabit Ethernet implementation


Figure 3-7:b

Gigabit Ethernet implementation


Figure 3-8:a

Token passing


Figure 3-8:b

Token passing


Figure 3-8:c

Token passing


Figure 3-8:d

Token passing


Figure 3-9

Data frame


Figure 3-10

MAU


Figure 3-11:a

Spread spectrum techniques


Figure 3-11:b

Spread spectrum techniques


Figure 3-12

ISM bands


Figure 3-13

BSSs


Figure 3-14

ESS


Figure 3-15

CSMA/CA


POINT-TO-POINTWANS

3.23.2


Figure 3-16

Band for ADSL


Figure 3-17

PPP frame


SWITCHEDWANS

3.33.3


Figure 3-18Frame Relay network


A cell network uses the cell as the basic A cell network uses the cell as the basic unit of data exchange. A cell is defined as unit of data exchange. A cell is defined as a small, fixed-sized block of information.a small, fixed-sized block of information.


Figure 3-19

ATM multiplexing


Figure 3-20

Architecture of an ATM network


Figure 3-21

Virtual circuits


Note that a virtual connection is defined by Note that a virtual connection is defined by a pair of numbers: the VPI and the VCI.a pair of numbers: the VPI and the VCI.


Figure 3-22

An ATM cell


Figure 3-23

ATM layers


The IP protocol uses the AAL5 sublayer.


We will discuss IP over ATM in Chapter 26.


Figure 3-24:a

ATM LAN architecture


Figure 3-24:b



Figure 3-24:c



Figure 3-25 A mixed architecture ATM LAN using LANE


CONNECTING DEVICES

3.43.4


Figure 3-26

Connecting devices


Figure 3-27

Repeater


A repeater connects segments of a LAN together.


A repeater forwards every packet; it has no A repeater forwards every packet; it has no filtering capability.filtering capability.


Figure 3-28

Hubs


A bridge has a table used in filtering A bridge has a table used in filtering decisions.decisions.


Figure 3-29

Bridge


A bridge connects segments of a LAN A bridge connects segments of a LAN together.together.


A router is a three-layer (physical, data A router is a three-layer (physical, data link, and network) device.link, and network) device.


A repeater or a bridge connects segments A repeater or a bridge connects segments of a LAN. of a LAN.

A router connects independent LANs or A router connects independent LANs or WANs to create an internetwork (internet).WANs to create an internetwork (internet).


Figure 3-30

Routing example


A router changes the physical addresses in A router changes the physical addresses in a packet. a packet.

Ch03

Technology

Transcript of Ch03