lecture one an introduction to networking. chapter one objectives examine the objectives of...

Lecture One

An Introduction

To Networking

Chapter One Objectives

Examine the objectives of networked computing relative to standalone computing

Identify the elements of a network Describe specific uses of a network Identify some of the certifications available

to networking professionals Identify the kinds of non-technical, or soft

skills to help in succeeding as a networking professional

Networks and Standalone Computers

Network– A group of computers and other devices connected

by some type of transmission media

– Networks enable users to share devices and data, collectively called a network’s resources

Standalone Computer– Uses programs and data only from its local

disks and is not connected to a network.

Sneakernet

Method of sharing data by copying it to a disk and carrying it from computer to computer

FIGURE 1-1 Data sharing before the advent of networks

Local and Remote Computers

Local Computer– Computer on which a user is working

Remote Computer– Computer which a user controls or works on

via a network connection

Local Area Network (LAN)

Network of computers and other devices confined to a relatively small space, e.g., campus of a university, a corporate site, or even one or a few rooms in a building.– Peer-to-Peer Communication– Server-Based Network

Peer-to-Peer Communication(for simple small networks with limited number of

computers)

Means of networking computers using a single cable

FIGURE 1-2 Simple peer-to-peer network

Server-Based Network(Coach House networks are server-based; in fact we have

several servers)

Network using special computers, known as file servers, to process data for and facilitate communication between other computers on the network– File Server

• Manages shared resources

– Client• Requests or services another computer on the

network

Server-Based Network

Workstation– Desktop computer, which may or may not be connected

to a network (most clients are workstation computers. Today, the line between workstations and a PCs has been blurred.)

Network Operating System (NOS)– Special system software designed to manage data and

other resources on a server for a number of clients– Coach House: servers run under Microsoft Window

NT and Sun Microsystems' Solaris NOS's.

Client/Server Architecture

Networking model in which clients use a central file server to share applications such as compilers, utility and other software.

FIGURE 1-3 LAN with a file server

Client/Server Architecture

FIGURE 1-4 An example of a complex network

Advantages of Server-Based over Peer-to-Peer Networks

User login accounts and passwords can be assigned in one place

Access to multiple shared resources can be centrally granted

Optimized to handle heavy processing loads and dedicated to handling requests from clients

Can connect more than a handful of computers

Wide Area Network (WAN)(Except T118, Coach House LANs have access to WAN/Internet)

Network connecting two or more geographically distinct LANs– The Internet is

an intricate and extensive WAN spanning the globe FIGURE 1-5 A simple WAN

Elements Common to AllServer-Based Networks

Client– Also refers to the human user of a client

workstation

Server Workstation

Elements Common to AllServer-Based Networks

Network Interface Card (NIC)– Device that

enables a workstation to connect to the network (usually pre-installed and comes as an integrated part of a PC or workstation.)

FIGURE 1-7 A network interface card (NIC)

Elements Common to AllServer-Based Networks

NOS (Network Operating System) Host (Server in server room; Coach House

has several servers)– Server that manages shared resources

Node– Any client, server, or other device on a network

identified by a unique identifying number

Elements Common to AllServer-Based Networks

Topology– Physical

layout of a computer network

FIGURE 1-7 Commonly used network topologies

Elements Common to AllServer-Based Networks

Protocol– Rules the network uses to transfer data; TCP/IP is the protocol for the

Internet. – Data Packets: a message or file is broken down into small segments

(known as packet); packets are transmitted and routed through the network individually in order to gain efficiency (higher utilization of the transmission media).

– The distinct units of data transmitted from one computer on a network to another

Addressing (will be discussed in more details in later chapters)– Scheme for assigning a unique identifying number to every workstation

or PC on a network– The number that uniquely identifies each workstation or device on a

network is its address.

Elements Common to AllServer-Based Networks

Transmission Media– Means through

which data is transmitted and received

– For LAN, twisted pair is the most common.

FIGURE 1-8 Examples of network transmission media

How Networks Are Used

Services– Features provided by a network

• File and Print Services

• Communications Services

• Mail Services

• Internet Services

• Management Services

Network Services

File Services– Allow users to share data files, applications,

and disk storage space Communications Services

– Allow remote users to connect to a network• Remote User

– Person working on a computer in a different geographical location from the LAN’s server

• Communications Server– Access Server

Network Services

Mail Services– Coordinate the storage and transfer of e-mail

between users on a network• Gateway

– Combination of software and hardware enabling two different kinds of networks to exchange data

Internet Services– Enable a network to communicate with the

Internet

Network Services

Management Services– Centrally administer and simplify complicated

management tasks on the network

– Numerous services fall under category of network management

– You as a network administrator will learn how to perform various administration tasks.

Important Management Services Traffic Monitoring and Control

– Traffic Data transmission and processing activity taking place on a computer network at any given time

– Segment• Part of a LAN separated from other parts of the LAN and that shares

Load Balancing– Distributing process activity evenly across a network so that

no single device is overwhelmed

These tasks are not a critical for our Coach House network; we have ample capacity to handle relatively light traffic.

Important Management Services Hardware Diagnosis and Failure Alert Asset Management

– Collecting and storing data on the number and types of software and hardware assets in an organization’s network

License Tracking– Determining how many copies of an application are

currently in use on a network

Coach House main Unix server hardware is covered by service contract. We do need to track the license and document the asset (equipment list distributed to all)

Important Management Services

Security Auditing– Evaluating security measures currently in place

on a network and notifying the network administrator if a security breach occurs

Software Distribution– Process of automatically transferring a data file

or program from the server to a client on the network

We have good track record!

Important Management Services Address Management (Managed by the

University; procedures on WPUNJ Web site)– Centrally administering a finite number of network

addresses for an entire LAN Backup and Restoration of Data

– Backing Up• Copying critical files to a secure storage area

– Restoring• Retrieving data if original files are lost

Very critical especially the system related files in the event the system crashes!

Becoming a Network Professional

Mastering the Technical Challenges Developing Your “Soft Skills” Pursuing Certification Finding a Job in Networking Joining Professional Associations

Mastering the Technical Challenges

Installing, configuring, and troubleshooting network file server software

Installing, configuring, and troubleshooting network file server hardware

Installing, configuring, and troubleshooting network client software

Installing, configuring, and troubleshooting network client hardware

Mastering the Technical Challenges

Understanding the characteristics of different transmission media

Understanding network design Understanding network protocols Understanding how users interact with the

network

Mastering the Technical Challenges

Specialty areas in high demand for networking professionals:– Network security– Internet and intranet design– Network management– Voice/data integration– Remote and mobile computing

Mastering the Technical Challenges

More specialty areas:– Data integrity and fault tolerance– In-depth knowledge of Microsoft networking

products– In-depth knowledge of NetWare networking

products– In-depth knowledge of router configuration and

management

Developing Your “Soft Skills”

Skills not easily measured but important to a networking career:– Customer Relations– Oral and Written Communications– Dependability!!!– Teamwork!!!– Leadership Abilities

Pursuing Certification

Certification– Process of mastering material pertaining to a

particular hardware system, operating system, programming language, or other program, then proving your mastery by passing a series of exams

Computer Technology Association (CompTIA)

Pursuing Certification

A+ Microsoft Certified Systems Engineer

(MCSE) Certified NetWare Engineer (CNE) Net+

Web Sites

TABLE 1-1

Web sites with job databases

Professional Association Sites

TABLE 1-2

Web sites of networking organizations

Chapter Summary

A Network is a group of computers or other devices connected by some type of transmission media

Networks may be small or large, connecting computers in one office or across the world

All networks offer advantages relative to the use of standalone computers

Chapter Summary

A LAN is a network of computers and other devices confined to a relatively small space

A WAN is a network connecting two or more geographically distinct LANs

All server-based networks share some common elements

The physical layout of a computer network is called a topology

Network protocols are the rules that the network uses to transfer data

Chapter Summary

File and print services provide the foundation for networking

Mail services allow networks users to exchange and store e-mail

Internet services enable organizations to connect to the Internet

Network management services centrally administer and simplify complicated management tasks on the network

Chapter Summary

Networking professionals are in demand Certification Hone your soft skills Numerous resources are available in

searching for networking positions Joining associations can benefit your

professional growth