Figure 5-1 Encapsulation

L1 Physical

L3 Network

L5 Session

L7 Applications

L2 Data Link

L4 Transport

L6 Presentation

Source Destination

Data

DataData

Data

Data Stream

Network Header

Network Header

Data

Data Stream

Data Stream

101010001011010101001010100010111110

Frame Header

Frame Trailer

L1 Physical

L3 Network

L5 Session

L7 Applications

L2 Data Link

L4 Transport

L6 Presentation

L = Layer - as L1 = layer 1

Figure 5-2 Data Encapsulation Process

Data

DataData

Data

Email Data Stream

Network Header

Network Header

Data

1010100010111101010101001010100010111110

Frame Header

Frame Trailer

Data

Segment

Packet

Frame

Bits

Email being Composed

Layer 4

Layer 3

Layer 2

Layer 1

Layer 5

Figure 5-3 OSI and TCP/IP models compared

Layer 6 Presentation

Layer 3 Network

Layer 1 Physical

Layer 2 Data Link

Layer 4 Transport

Layer 5 Session

Layer 7 Application

Link

Network

Transport

Application

OSI Model TCP/IP Model

Figure 5-4 An example of a peer-to-peer network

Figure 5-5 An example of a client/cerver network

Server

Client

Figure 6 - Star Topology

Workstation

Server Controller

Figure 5-7 A Bus Topology

Server

Printer

workstation

Computer

Figure 8- Ring Topology

Workstation

Server

Figure 5-9 A CSMA/CD collision

A

B

A

B

A

B

A

B

Clear to

send

Clear to

send

collision

Sending

Sending

Wait random

time

1 2 3 4

Figure 5-10 Collision Domain

Collision Domain

1

Collision Domain

2

or

or Router

Switch

Bridge

Figure 5-11 Modular Jack and Active Hub

RJ45Active Hub

Figure 5-12 A network segment built on a 10 Mbps hub

2 Mbps

10 Mbps2 Mbps

2 Mbps

2 Mbps 2 Mbps

Figure 5-13 Bridging Two Network Segments

A

D

CB

E F

01-3A-2D-6C-0C-2A 01-20-2D-7C-DC-43

01-A2-1D-75-B1-12 01-0B-0D-7C-1F-3D 00-20-6D-7C-01-BC

Segment 1

Segment 2

01-20-0D-7C-01-9A

Bridge

Figure 5-14 An Example of a Switched Ethernet Configuration

EDC

A

B

Server

Ethernet Switch

Workstation

100 Mbps100 Mbps

100 Mbps

100 Mbps

100 Mbps

100 Mbps

Figure 5-15 A VLAN environment

D

Internet or WAN

Accounting

Marketing

Engineering

Server Farm

Figure 5-16 Point-to-Point and Multipoint (daisy-chained)

LAN

CSU/DSU

CSU/DSU

CSU/DSU

CSU/DSU

CSU/DSU

CSU/DSU

LAN

LAN

Paris

Rome

New York

Chicago

LAN

LANCSU/DSU

CSU/DSU

CSU/DSU

CSU/DSU

LAN

LAN

Paris

Rome

New York

Chicago

LAN

Point-to-Point

Multipoint

Figure 5-17 X.25 Pack Switched Network

1

2

3

4

5

6

7

8

9

A4th1-2-3-4-6-5-7-8-9 (longest path)A

D3rd1-2-6-5-6-8-9D

C1st1-3-5-8-9 (shortest path)C

B2nd1-2-4-5-8-9B

Re-Ordered and delivered to computer

“Z”

Packet Arrives at “9”Path Taken

Packets: A, B, C, and D Leave Computer “Y”

via“1”

Computer “Y”

Computer “Z”

Figure 5-18 Statistical Pack switching

Virtual Circuit

B

A

C

A A

AA

AAA

C C C CC

CCB B B B B BBBPacket

Switch

Data Flow

Time Division Multiplexing

Figure 5-19 Combining different services onto a single access channel

Multiplexed cell stream

B

A

C

A A

AA

AAA

C C C CC

CCB B B B B BBBATM

Multiplexer

Data Flow

Voice

Video

Data

Figure 5-22 PVCs in a Frame Relay network

LAPD

SP

LAPD

LAPD

LAPD

LAPDLAPD

LAPD

LAPD

SP

SP

SP

SP

SP

SP = Switch Point

PVC =

DTE or FRAD =

Figure 5-21 Frame Relay frame format (LAPD)

Figure 5-22 Frame Relay bandwidth-on-demand

Collision Domain

Figure 5-12 A Combination of interconnections

Figure 5-13 Three Tiered Network Hierarchy

Figure 5-17Data Service Components

Figure 5-17 DDS Components

DTE DTECSU/DSU CSU/DSUDDS Hub DDS Hub

Physical interfaceV.35

Data Access Lines

Data Access Lines

Physical interfaceV.35

Long-distance digital channel

Figure 5-18 Pack switching

PS

PS

PS

PSPS

PS

PSPS

PS

Terminal

SDLC Host

X.25 Host

RJE Station

Asynch Terminal

Terminal

PS = Packet Switch

Figure 5-1 The OSI model versus the TCP stack

Figure 5-2 An example of a shared-medium LAN

Figure 5-3 An example of Gigabit Ethernet

Figure 5-4 Token passing

Figure 5-5 CSMA/CD

Figure 5-6 Collision Domains

Figure 5-7 RJ45 modular jack and Active Hub

Figure 5-8 shows a network that uses a combination of interconnection

Figure 5-9 Bridging two network segments

Figure 5-10 An example of a switched Ethernet configuration

Figure 5-11 An Ethernet switch

Figure 5-12 A VLAN

Figure 5-13 A three layer network hierarchy

Figure 5-14 Data service components

Figure 5-15 Point to Point leased line and multipoint (daisy chained)

Figure 5-16 DDS components

Figure 5-17 Packet switching

Figure 5-18 Statistical Packet Switching

Figure 5-19 An X.25 packet-switched network

Figure 5-20 Frame Relay frame format (LAP D)

Figure 5-21 PVCs in a Frame Relay network

Figure 5-22 Frame Relay bandwidth-an-demand

Figure 5-23 Combining different services onto a single access channel