Chapter01 -- introduction to networking

Chapter 1: Introduction to Networking

Network+ Guide to Networks

Objectives

List the advantages of networked computing relative to standalone computing

Distinguish between client/server and peer-to-peer networks

List elements common to all client/server networks

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Objectives (continued)

Describe several specific uses for a network

Identify some of the certifications available to networking professionals

Identify the kinds of non-technical, or “soft,” skills that will help you succeed as networking professional

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A Network is:

• A group of computers and other devices (such as printers) that are connected by some type of transmission media, such as copper or fiber-optic cable or the atmosphere, in the case of wireless transmission.

• As small as two computers connected by a cable in a home office or as large as several thousand computers connected across the world via a combination of cable, phone lines, and satellite links.

• Connecting personal computers, networks may link mainframe computers, printers, plotters, fax machines, and phone systems.

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Why Use Networks?

• Manage or Administer resources on multiple computers from a central location

• Networks—enable multiple users to share devices and resources such as:• Printers

• Faxes

• Programs and Files

• Word Processing

• Spread Sheets

• Data Base

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Types of Networks

•Peer-to-peer Networks

•Client/Server Networks

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Peer-to-peer Networks

• Simple to configure

• Don’t need much technical expertise

• Typically less expensive to setup

• Suitable for environments where saving money is critical

• Not very flexible

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Peer-to-peer Networks (continued)

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Client/Server Networks• Servers facilitate communication and resource sharing

between other computers on the network known as clients

• Networks that use a server to enable clients to share data, data storage space, and devices is known as a client/server network

• Computers on a client/server network act as a client or a server

• To function as a server, a computer must be running a network operating system (NOS), a special type of software designed to manage data and other resources for a number of clients

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Client/Server Network (continued)

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Advantages Over Peer-to-Peer Networks

• Client Servers offer:

• User login accounts and passwords for anyone on a server-based network can be assigned in one place

• Access to multiple shared resources (such as data files or printers) can be centrally granted to a single user or groups of users

• Problems on the network can be tracked, diagnosed, and often fixed from one location

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Advantages Over Peer-to-Peer Networks (continued)

• Servers are optimized to handle heavy processing loads and dedicated to handling requests from clients, enabling faster response time

• Because of their efficient processing and larger disk storage, servers can connect more than a handful of computers on a network

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LANs, MANs, and WANs

• LAN – Local Area Network

• MAN – Metropolitan Area Network

• WAN – Wide Are Network

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Local Area Network (LAN)

• A network of computers and other devices that is confined to a relatively small space, such as one building or even one office

• Interconnected and rely on several servers running many different applications and managing resources other than data

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Complex Network

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Metropolitan AreaNetwork (MAN)

• A network that is larger than a LAN and connects clients and servers from multiple buildings

• A MAN may use different transmission technology and media than a LAN because of the distance it covers

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Wide Area Network (WAN)• A network that connects two or more geographically distinct

LANs or MANs

• WANs carry data over longer distances than LANs

• WANs require slightly different transmission methods and media and often use a greater variety of technologies than LANs

• Most MANs can also be described as WANs

• WANs commonly connect separate offices in the same organization, whether they are across town or across the world from each other

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Wide Area Network (WAN)(continued)

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Elements Common To All Client Server Networks

• Client. A computer on the network that requests resources or services from another computer on a network. In some cases, a client could also act as a server. he term “client” may also refer to the human user of a client workstation

• Server. A computer on the network that manages shared resources and usually have more processing power, memory, and hard disk space than clients. They run network operating software that can manage not only data, but also users, groups, security, and applications on the network

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Elements Common To All Client Server Networks (continued)

• Workstation. A desktop computer, which may or may not be connected to a network. Most clients are workstation computers

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• Network interface card (NIC). The device inside a computer that connects a computer to the network media, thus allowing it to communicate with other computers. Several companies (such as 3Com, IBM, Intel, SMC, and Xircom) manufacture NICs, which come with a variety of specifications that are tailored to the requirements of the workstation and the network. NICs are also known as network adapters

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• Network operating system (NOS). The software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions

• The most popular network operating systems are Microsoft Windows Server 2003, Novell NetWare, and UNIX

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• Host. A computer that enables resource sharing by other computers on the same network.

• Node. A client, server, or other device that can communicate over a network and that is identified by a unique number, known as its network address

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• Topology. The physical layout of a computer network. Topologies vary according to the needs of the organization and available hardware and expertise. Networks are usually arranged in a ring, bus, or star formation; hybrid combinations of these patterns are also possible

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Network Topologies

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• Connectivity device. One of several types of specialized devices that allows two or more networks or multiple parts of one network to connect and exchange data

• Protocol. A pre-determined method or format for exchanging data between computers. Protocols ensure that data are transferred whole, in sequence, and without error from one node on the network to another. To maintain and manage a network effectively, you must have a thorough understanding of network protocols

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• Data packets. The distinct units of data that are transmitted from one computer on a network to another. Breaking a large stream of data into many packets allows a network to deliver that data more efficiently and reliably

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• Addressing. The scheme for assigning a unique identifying number to every workstation and device on the network

• Transmission media. The means through which data is transmitted and received. Transmission media may be physical, such as wire or cable, or atmospheric (wireless), such as radio waves

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How Networks Are Used

• Functions provided by a network are usually referred to as network services

• File and Print Services• File services: share data files, applications and disk

storage space

• Print services: share printers across a network

• Communications Services• Allow remote users to connect to the network

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How Networks Are Used (continued)

• Mail Services• Intercept or filter unsolicited e-mail

• Find objectionable content

• Route messages according to particular rules

• Provide a Web-based client for checking e-mail

• Notify if certain events occur

• Schedule e-mail transmission, retrieval, storage, and maintenance functions

• Communicate with mail servers on other networks

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• Internet Services• Web server to supply Web pages upon demand

• Other Internet services include:

• file transfer

• Internet addressing schemes

• security filters

• means for directly logging on to other computers

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• Management Services• Centrally administer management tasks on the

network

• Traffic monitoring and control

• Load balancing

• Hardware diagnosis and failure alert

• Asset management

• License tracking

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• Centrally administer management tasks on the network (cont.)

• Security auditing

• Software distribution

• Address management

• Backup and restoration of data

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Becoming a Network Professional

• Mastering the Technical Challenges• Acquire these skills:

• Installing, configuring, and troubleshooting network

• Server and Client software and hardware

• Understanding different transmission media

• Understanding network design

• Understanding network protocols

• Understanding how users interact with the network

• Constructing a network with clients, servers, media, and connectivity devices

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Becoming a Network Professional (continued)

• Mastering the Technical Challenges (cont.)• Specialties in high demand:

• Network security

• Voice/data integration

• In-depth knowledge about one or more NOSs

• Network management

• Internet and intranet design

• Configuration and optimization of routers and switches

• Centralized data storage and management for large-scale environments

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• Developing Your “Soft Skills”

• Customer relations

• Oral and written communications

• Dependability

• Teamwork

• Leadership abilities37


• Pursuing Certification• Benefits to becoming certified:

• Better salary

• Greater opportunities

• Professional respect

• Access to better support

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• Finding a Job in Networking• Search the Web

• Classified ad section of local newspaper

• Visit a career center

• Network with like-minded professionals

• Attend career fairs

• Enlist a recruiter

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• Joining Professional Associations

• Association for Computing Machinery (ACM)

• www.acm.org

• Association for Information Technology Professionals

• www.aitp.org

• Chinese Information and Networking Association

• www.cina.org40


• IEEE Computer Society

• www.computer.org

• Women in Technology International (WITI)

• www.witi.org

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Summary

• Network is a group of computers and other devices

• Networks offer advantages

• Peer-to-peer network, every computer can communicate directly with every other computer

• Traditional peer-to-peer networks consist of two or more personal computers

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Summary (continued)

• Traditional peer-to-peer networks are usually simple and inexpensive

• Client/server networks rely on a centrally administered server

• Client/server networks are more complex and expensive

• Servers typically possess more processing power, hard disk space, and memory

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Summary (continued)

• Local area network (LAN) is a network of computers and other devices

• LANs can be connected to form wide area networks (WANs)

• All client/server networks share some common elements

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Summary (continued)

• Networks provide services for e-mail, printing, file sharing, Internet access, remote access capabilities, and network management

• File and print services provide the foundation for networking

• Networks use communications services to allow remote users to connect

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Summary (continued)

• Mail services allow users on a network to exchange and store e-mail

• Internet services enable organizations to connect to and use the global Internet

• Network management services

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Summary (continued)

• Prepare yourself for a networking career

• Certification is the process of mastering material

• Hone your soft skills

• Joining an association for networking professionals

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