UNIT 9 – COMPUTER NETWORKS

ASSIGNMENT TASKS – Assignment 1

AIMS:

To know the types of network systems and related standards and protocols

CRITERIA:

P1 – Describe the types of networks available and how they relate to particular network standards and protocols

P2 – Describe, using examples, why different network standards and protocols are necessary

P3 – Explain the key components required for client workstations to connect to a network and access network resources

P4 - Explain the function of interconnection devices

M1 – Compare the benefits and disadvantages of peer-to-peer network and client/server networks

Task 1: Description of the Types of Networks:

1. TYPES OF NETWORK

1.  LANs – Local Area Networks

Provide a definition of a LAN

What are they used for?

How are they structured?

What is a VLAN?

2.  WANs – Wide Area Networks

Provide a definition of a WAN

(The interconnection of various types of LANs)

Provide examples including Janet & the Internet

3.  WAN Technologies

Provide a description of a Frame Relay

Explain what a packet-switched network structure is?

Provide a simple example diagram of a Frame relay configuration

ATM – Asynchronous Transfer Mode

Provide a definition

What are the differences and advantages over Frame Relay

MPLS – Multi Protocol Labelled Switching

Provide a brief description

Explain differences to ATM and Frame Relay

4.  VANs – Value Added Networks

Explain the usage of VANs

How are they used by home users and commercial organisations?

5.  MANs – Metropolitan Area Network

PANs – Personal Area Networks

Brief descriptions of these network types

2. NETWORK TOPOLOGY (see Powerpoint)

The structure or layout of the communications network.

Each system has a physical and a logical topology

For each of the following topologies:

1.  Provide a diagrammatic representation of the layout

2.  Provide a brief description of the layout

3.  List the main advantages and disadvantages of the topology

Topologies:

1.  Bus Topology

2.  Ring Topology

3.  Star Topology

4.  Mesh Topology

5.  Tree Topology

3. NETWORK ACCESS METHODS

Describe with the aid of a diagram how devices access the network to send data for the following two configurations:

1.  TOKEN RING:

Connection of devices in a logical ring

Data carried by a software token

Accessing the free token

Sending data to other devices in the ring

What are the advantages and disadvantages of this method.

2.  ETHERNET:

CSMA/CD – Carrier Sense Multiple Access / Collision Detection

CSMA/CA – / Collision Avoidance

Listening / sensing when channel free to send data

Two devices sending at the same time can cause a collision

Back–off time before resending data

In CA (Wireless systems) – detection of other signals before sending

4. OSI 7 LAYER MODEL (See Powerpoint & Handout)

TCP/IP 4 LAYER MODEL (See Powerpoint & Handout)

5. FACTORS IN CHOOSING A NETWORK TO MEET BUSINESS NEEDS

1.  Technical expertise in maintenance

2.  Current available technology

3.  Region / area where network is to be implemented

4.  What technologies are supported in that area

5.  Costs

6.  Size required

7.  Speed required

8.  Traffic requirements – usage of the network & number of users

6. NETWORK PROTOCOLS AND STANDARDS

For effective network communication the system and its devices require a range of protocols to provide consistency and reliability

Each protocol is used for a different purpose depending on what data is transmitted

TCP/IP – Transmission Control Protocol / Internet Protocol

Inter-communication between LANs and WANs (eg Internet)

Provide a diagram to show the TCP/IP 4 layer model and show how it is related to the OSI 7 layer model. Show the range of protocols associated with each of these 4 layers

Provide a brief description of the following protocols

FTP – File Transfer Protocol

HTTP – Hypertext Transfer Protocol

POP 3 – Post Office Protocol

SMTP – Simple Mail Transfer Protocol

DNS – Domain name System

TCP – Transmission Control Protocol

UDP – User Datagram Protocol

IP – Internet Protocol

ICMP – Internet Control Messaging Protocol

DHCP – Dynamic Host Configuration Protocol

ARP & RARP – Address Resolution Protocol

What is the AppleTalk suite of protocols?

The following are known as the Application Layer Protocols for using the Internet or email:

HTTP

FTP

SMTP

DNS

DHCP

6. LAN STANDARDS

IEEE – Institute of Electrical & Electronic Engineers

To maintain LAN standards for the communication at OSI layer 2

Briefly describe each of the following standards:

IEEE 802.2 – Management of Ethernet Data Packets

IEEE 802.3 – Definition of MAC Addressing (NIC)

IEEE 802.5 – Token Passing Management

Provide a description of FDDI

FDDI – Fibre Distributed Data Interface

7. WIRELESS TECHNOLOGIES

The following standards for connectionless systems:

IEEE 802.11 – Wireless Standards (WiFi)

Bluetooth

3G / 4G (Mobile Phone Technology)

InfraRed Standards – IrDa

8. NETWORK DEVICES (Purpose-Features)

Workstations

Computer terminal, Mobile phone, PDA, Blackberry, Laptop, Television, Game console, Internet telephone

Servers:

File Servers – Files, Data, Application Software

Web Servers – Web Sites, Data, Communication, E-Commerce

Email Servers – Communications

Print Servers – Shared printing

Security Servers – Proxy or Firewall access

Address Servers – DNS / DHCP

Network Interface Cards (NICs)

UTP network cards

Wireless adapters

Bluetooth transceivers

Fibre optic cards

External adapters – dongles

PXE – Remote booting

9. INTERCONNECTION DEVICES (Purpose & Features)

Routers

Switches

Wireless Access points

(modem)

(hub)

(repeater)

(bridge)

(gateway)

10. CONNECTORS & CABLING

Leased Lines

Dedicated Lines

Media – UTP / STP, Coaxial, Fibre Optic cabling

Wireless

Microwave

Satellite

Mobile Technology

Cable connection standards

11. SOFTWARE

Network Operating Systems:

Peer to Peer

Client Server

Virus checking

Firewalls

Email Client

Commercial Systems