Introduction To Networking

Introduction to Networking

Why use networks?Physical network structureNetwork ServersNetwork ClientsNetwork Operating SystemsLANs and WANs

What Is A Network?

Why Use Networks?Sharing…

DataSoftwarePrintersProcessing powerAccess to the Internet

Controlling…SecurityAdministration

The Network Server

Printing

Data

Software

Access to the Internet

The Network Client

Uses Resources

Write file to drive C:

Write file to drive X:

Peer-To-Peer Networks

Using

Using

Using

Using

Sharing

Sharing Sharing

Limitations

300 ft. effective range from access point1400 ft maximum range

Structural interferenceInterference from other devices such as

cordless phones.

Client/Server Networks

Using

Sharing

Using Using

Network Operating Systems

Several productsMicrosoft Windows NT/2000/2003Novell NetwareBanyan Vines etc

All run on the server and share resourcesHard disk spacePrinters etc

Directory Services

Centralized control of all network resourcesMicrosoft Windows 2000

Active DirectoryNovell Netware

Network Directory Services (NDS)Banyan Vines

Network Interface Card

Physical interface for the PC to the cable

Can be add-on adapter PCMCIA/Cardbus ISA/EISA PCI

Often built into motherboard Has a unique physical address

(MAC Address)

Network Cables

CoaxialThin and Thick Ethernet (10Base2,

10Base5) – used to transmit videoUnshielded Twisted Pair (UTP)

10baseT, 100baseT (most commonShielded Twisted Pair (STP)Fiber-optic

Local Area Networks (LANs)

Wide Area Networks (WANs)

Cable-Less (i.e. Wireless) Connections

Narrow band radio transmission (RF)Subject to interferenceSecurity issues

Infra-red transmission (IR) Line of sight requiredOther light sources can interfereEx. Palm beaming/CPS “clickers”

Standards

IEEE 802.11.b –2.4GHz – 11MbpsIEEE 802.11.a – 5GHz – 54 MbpsIEEE 802.11g – 2.4Ghz – Hybrid

11/54Mbps (most common)New! IEEE 802.11n – up to 100

Mbps

Security Overview

WEP - Wired Equivalent Privacy 40 bit vs. 128 bit

Is Encryption Necessary?

Open access vs. Secured

Other Security MeasuresContent Filtering

Network Partitioning

Applications

Any application currently used on a traditional wired network can be used on a wireless network.

New applications may be available or can be developed to take advantage of wireless, such as Wireless PDA access to a card catalog.

Wireless Network Components

Access Points NICs – Network Interface Cards

PCMCIA USB PCI CompactFlash

Other Wireless Devices Bridges and Routers Print Servers

PCs, Laptops, PDAs, even Projectors

Security (Encryption, Content Filtering, Privacy, etc.)

Content Filtering & Proxy ServersWeb content filtering that has generally been

software on the desktop would have to be handled by a server if people are allowed to use their own laptops. Note: This is required by CIPA for all government organizations, including schools.

Proxy servers allow you to control what information people have access to. This is a good practice anyway, allowing you to control at a global level what information travels over your network. It also allows you to track usage.

Security (Encryption, Content Filtering, Privacy, etc.)

Viruses and HackerWireless does not add any additional threat

in the way of viruses. Anyone, anywhere can attack a network

that is connected to the Internet. Wireless does not increase that chance. Security measures such as firewalls, can reduce the risk.

Why Deploy Wireless?

Cost savings over wireline.Can not run wire to locations needed.To enable patrons to bring their own

laptop, therefore reducing the cost of owning many PCs.

To enable you to easily move PCs.To be on the leading edge.

Cost

802.11b Wireless Access Points start around $100.00 for basic connectivity and run up to $500.00 for more management features.

802.11b Network Interface Cards (NICs) cost between $50-$100 and come in USB, PCI (desktop), PCMCIA (laptop) and CompactFlash versions.

Bluetooth – 802.15

Bluetooth is the standard for wireless personal area networks or WPAN. It allows high speed transmission of data over very short distances.

Bluetooth is normally used for transferring data between laptops or devices, or in Internet Kiosk type applications where roaming is not needed.

Networking Technology Review

Why use networks?Physical network structureNetwork ServersNetwork ClientsNetwork Operating SystemsLANs and WANs