btec nat it business - principles of networking1 unit 27: principles of computer networks...

BTEC Nat IT Business - Principles of NetworkingBTEC Nat IT Business - Principles of Networking 11

Unit 27: Unit 27: Principles of Computer Principles of Computer

NetworksNetworks

Introduction to NetworksIntroduction to Networks

Network TypesNetwork Types


AimsAims

Different types of Networks revisedDifferent types of Networks revised Understand the purpose of a Understand the purpose of a

computer networkcomputer network Create network drawingsCreate network drawings Understand PacketsUnderstand Packets


What is the purpose of a What is the purpose of a network?network?

Enables file sharing (should cut down on Enables file sharing (should cut down on printing costs)printing costs)

Share resources, such as printers, Share resources, such as printers, scanners, etc., to get more use out of scanners, etc., to get more use out of office equipment (cutting down costs)office equipment (cutting down costs)

Share software with multi-user licenses.Share software with multi-user licenses. Perform data backups quicker and easier Perform data backups quicker and easier

with files on shared drives.with files on shared drives. Easier and more manageable Internet Easier and more manageable Internet

connectionconnection


Types of NetworkTypes of Network LAN (Local area network)LAN (Local area network)

The definition of a LAN has become increasingly The definition of a LAN has become increasingly vague over the last ten years.vague over the last ten years.

It was understood that it was interconnected It was understood that it was interconnected computers at one location i.e. college or a computers at one location i.e. college or a workplace.workplace.

Know due to faster technology LAN devices can Know due to faster technology LAN devices can be used over longer distances.be used over longer distances.

A LAN can be as small as two computers by A LAN can be as small as two computers by using a simple Ethernet connection or can using a simple Ethernet connection or can divided into sub networks using switches and divided into sub networks using switches and routers.routers.

Local Area Network - LANLocal Area Network - LAN

Single campusSingle campus Can be multiple networks interconnectedCan be multiple networks interconnected No special telecommunications hardware No special telecommunications hardware

is necessary, as cables/signals never leave is necessary, as cables/signals never leave the company’s premisesthe company’s premises

Fast data transfer ratesFast data transfer rates reliability of transmission not always top reliability of transmission not always top

prioritypriority damaged data can be re-transmitted easilydamaged data can be re-transmitted easily

Video-conferencing is feasibleVideo-conferencing is feasible55


TaskTask Using Visio try to recreate the LAN shown Using Visio try to recreate the LAN shown

below. (Feel free to make it your own)below. (Feel free to make it your own)


Types of NetworkTypes of Network WAN (Wide area network)WAN (Wide area network)

A WAN is a complex network system, A WAN is a complex network system, comprising of interconnected LANs.comprising of interconnected LANs.

WANs are used to connect LANs and other WANs are used to connect LANs and other types of networks together, so that users and types of networks together, so that users and computers in one location can communicate computers in one location can communicate with users and computers in other locations.with users and computers in other locations.

WANs are often built using leased lines.WANs are often built using leased lines.A router connects to the LAN on one side and a A router connects to the LAN on one side and a hub within the WAN on the otherhub within the WAN on the other

Network protocols including TCP/IP deliver Network protocols including TCP/IP deliver transport and addressing functions.transport and addressing functions.

Wide Area Network - WANWide Area Network - WAN The rest of the planetThe rest of the planet Slower data transfer rates (end to end)Slower data transfer rates (end to end)

reliability is a high priorityreliability is a high priority retransmission of missing data is a large retransmission of missing data is a large

overheadoverhead extensive use of external extensive use of external

telecommunication systemstelecommunication systems backbone transfer rate is now faster than backbone transfer rate is now faster than

LANs!LANs! The InternetThe Internet International telecommunicationsInternational telecommunications Satellite systemsSatellite systems

e.g. Global Positioning System - GPSe.g. Global Positioning System - GPS88


http://en.wikipedia.org/wiki/Wide_area_network

Several options are available for WAN connectivity:


WANWAN

Janet backboneJanet backbone All UK academic institutions All UK academic institutions

access the internet via the access the internet via the Janet networkJanet network .ac.uk domain.ac.uk domain

Funded by Funded by Joint Information Joint Information Systems CommitteeSystems Committee ( (JISCJISC) )

In October 2006 SuperJANET5 was In October 2006 SuperJANET5 was launched after £29 million of launched after £29 million of investment. investment.

It provided an upgrade path to It provided an upgrade path to 40GBit/s. 40GBit/s.

Most organisations connected by Most organisations connected by twenty WANstwenty WANs

1111

Map from http://www.janet.ac.uk/about/topology/SJ5-topology-map.pdf

WAN TECHNOLOGIESWAN TECHNOLOGIES

FRAME RELAYFRAME RELAY ATM – ASYNCHRONOUS TRANSFER ATM – ASYNCHRONOUS TRANSFER

MODEMODE MPLS – MULTI-PROTOCOL LABELLED MPLS – MULTI-PROTOCOL LABELLED

SWITCHINGSWITCHING


FRAME RELAYFRAME RELAY

PACKET PACKET SWITCHINGSWITCHING

MESH MESH CONNECTIONSCONNECTIONS

CORE OF A WANCORE OF A WAN Monitors traffic on Monitors traffic on

system – re-routingsystem – re-routing Directs traffic from Directs traffic from

system to systemsystem to system CheapCheap


ATMATM

Data cells smaller Data cells smaller than packetsthan packets

FasterFaster Separate voice and Separate voice and

data data communicationscommunications

Used with SkypeUsed with Skype Similar functions to Similar functions to

Frame RelayFrame Relay


MPLSMPLS

Most recent Most recent successorsuccessor

Cooperates with Cooperates with routing protocolsrouting protocols

Highly adaptableHighly adaptable Adjusts to changes in Adjusts to changes in

networksnetworks Directs data from one Directs data from one

network node to network node to another using short another using short path labels not long path labels not long network addressesnetwork addresses



Types of NetworkTypes of Network MAN (Metropolitan area networks)MAN (Metropolitan area networks)

A Metropolitan Area Network (MAN) is a large computer A Metropolitan Area Network (MAN) is a large computer network that spans a metropolitan area or campus. The network that spans a metropolitan area or campus. The network size falls intermediate between LANs and WANs.network size falls intermediate between LANs and WANs.

MANs provide Internet connectivity for LANs in a MANs provide Internet connectivity for LANs in a metropolitan region, and connect them to wider area metropolitan region, and connect them to wider area networks like the Internet. networks like the Internet.

They typically use wireless infrastructure or optical fiber They typically use wireless infrastructure or optical fiber (or fibre) connections to link their sites.(or fibre) connections to link their sites.

A MAN (like a WAN) is not generally owned by a single A MAN (like a WAN) is not generally owned by a single organisation. The MAN, its communications links and organisation. The MAN, its communications links and equipment are generally owned by either a consortium equipment are generally owned by either a consortium of users or by a network service provider who sells the of users or by a network service provider who sells the service to the users. service to the users.

Metropolitan Area Network - Metropolitan Area Network - MANMAN

Multiple campusesMultiple campuses e.g. within a citye.g. within a city

small geographical areasmall geographical area

Australians use MANs to interconnect Australians use MANs to interconnect South Eastern citiesSouth Eastern cities

Slower data transfer rates?Slower data transfer rates? need reliability of WANs with speed of need reliability of WANs with speed of

LANsLANs1717

VAN – Value Added VAN – Value Added NetworksNetworks

Hosted seviceHosted sevice Like a regional Post OfficeLike a regional Post Office Intermediatory between business Intermediatory between business

partners sharing standards or datapartners sharing standards or data Transmits data by EDI or as XMLTransmits data by EDI or as XML Routes, stores & delivers EDI messagesRoutes, stores & delivers EDI messages EDI – Electronic Data Interchange – EDI – Electronic Data Interchange –

transfers electronic documents or transfers electronic documents or business data from one partner system business data from one partner system to anotherto another


PAN – Personal Area NetorkPAN – Personal Area Netork

Interconnects devices in an individual Interconnects devices in an individual person’s workspaceperson’s workspace

Wireless connections – BluetoothWireless connections – Bluetooth Can connect to a higher level network Can connect to a higher level network

or Internetor Internet Bluetooth – short range radio waves up Bluetooth – short range radio waves up

to 10 metresto 10 metres Computers, cell phones, PDAs, Computers, cell phones, PDAs,

headsets, mouse or other pointing headsets, mouse or other pointing devicesdevices



Types of NetworkTypes of Network

Mesh networkMesh network A netlike communications network in A netlike communications network in

which there are at least two pathways to which there are at least two pathways to each node.each node.

A fully meshed network means that every A fully meshed network means that every node has a direct connection to every node has a direct connection to every other node. Most mesh networks are other node. Most mesh networks are partially meshed and require traversing partially meshed and require traversing nodes to go from each node to every nodes to go from each node to every other. other.


TaskTask

Using the internet look into what a Using the internet look into what a packet is.packet is.

Create a network diagram in Visio to Create a network diagram in Visio to represent “SuperJanet”.represent “SuperJanet”.

PacketPacket A A packetpacket is a formatted is a formatted unit of data unit of data carried carried

by a by a packet mode computer networkpacket mode computer network. . Computer communications links that do not Computer communications links that do not

support packets, such as traditional point-to-support packets, such as traditional point-to-point telecommunications links, simply point telecommunications links, simply transmit data as a series of transmit data as a series of bytesbytes, , characterscharacters, or , or bitsbits alone. alone.

When data is formatted into packets, the When data is formatted into packets, the bitratebitrate of the communication medium can of the communication medium can better be shared among users than if the better be shared among users than if the network would have been network would have been circuit switchedcircuit switched. .

By using packet switched networking it is By using packet switched networking it is also harder to guarantee a lowest possible also harder to guarantee a lowest possible bitrate. bitrate.



ConclusionConclusion

Considered the purpose of a Considered the purpose of a computer networkcomputer network

Revised some of the different types Revised some of the different types of networksof networks

Used Visio to create network Used Visio to create network diagramsdiagrams

Gained an understanding of a PacketGained an understanding of a Packet

btec nat it business - principles of networking1 unit 27: principles of computer networks...

Documents

business principles

networkingbtec nat

wanbtec nat

ownbtec nat

networksnetwork typesbtec

prioritydamaged data

interconnected computers

complex network system