Chapter 1 An Introduction to Networking Collected and Compiled By JD Willard MCSE, MCSA, Network+, Microsoft IT Academy Administrator Computer Information Systems Instructor Albany Technical College

Attention: Accessing Demos This course presents many demos. The Demos require that you be logged in to the Virtual Technical College web site when you click on them to run. To access and log in to the Virtual Technical College web site: –To access the site type in the url windowwww.vtc.com –Log in using the username: CIS 1140 or ATCStudent1 –*Enter the password: student If you should click on the demo link and you get an Access Denied it is because you have not logged in to vtc.com or you need to log out and log back in. *Remember that passwords are case sensitive so enter it in all lower case letters.

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

Why Use Networks? Network: group of computers and other devices that are connected by some type of transmission media Commonly connected devices include microcomputers, minicomputers, mainframe computers, terminals, printers, fax machines, pagers, and various data storage devices Advantages of using networks over standalone computers: –Networks enable multiple users to share the network’s resources (devices and data) –Networks allow you to manage, or administer, resources on multiple computers from a central location What Is A Network Demo

What Are the Benefits of Computer Networking? Powerful, Flexible Collaboration Cost-Effective Resource Sharing Secure Management of Sensitive Information Effective Worldwide Communications Easy, Immediate Information Dissemination Worldwide, Instantaneous Access to Information

Types of Networks: Peer-to-peer Networks Every computer can communicate directly with every other computer By default, no computer has more authority than another No centralized security. Security is maintained on each individual computer (decentralized security model) Every computer is capable of sending and receiving information to and from every other computer Network Models Demo

Peer-to-peer Networks Resource sharing on a simple peer-to-peer network No dedicated server or hierarchy, also called a workgroup. Usually 10 or fewer workstations. Users act as their own administrator and security. Computers are in same general area. Limited growth. Peer to Peer vs. Server Centric Demo

Client/Server Networks Server: central computer used to facilitate communication and resource sharing between other computers (called clients) on the network (centralized security model) Client/server network: uses a server to enable clients to share data, data storage space, and devices To function as a server, a computer must be running a network operating system (NOS) Most of the concepts on the Network+ exam pertain to client/server networks

Client/Server Networks Resource sharing on a client/server network 10 or more users. Employs specialized servers. –File and Print –Application –Mail –Fax –Communications (gateways) Central administration. Greater security. Centralized backup. Data Redundancy. Supports many users

Client/Server Networks Advantages of using client/server networks over peer-to-peer networks: –User logon accounts and passwords can be assigned in one place –Access to multiple shared resources can be centrally granted to a single user or groups of users –Problems can be tracked, diagnosed, and often fixed from one location –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

LANs Local Area Networks Local area network (LAN): confined to a relatively small space, such as a building or an office Typically connects computer in a single building or campus. Developed in 1970s. Medium : optical fibers, coaxial cables, twisted pair, wireless. High speed networks Typically buses or rings. Ethernet, Token Ring Network Categories Demo

MANs Metropolitan area network Larger than a LAN; connects clients and servers from multiple buildings Generally covers campuses or office complexes Developed in 1980s Medium : optical fibers, twisted pair cables Data rates adequate

WANs Wide area network Connects two or more geographically distinct LANs or MANs Developed in 1960s. Generally covers large distances (states, countries, continents). Medium : communication circuits connected by routers. Routers forwards packets from one to another following a route from the sender to the receiver. Store-and-Forward Hosts are typically connected (or close to) the routers

LANs, MANs, and WANs A simple WAN

Elements Common to Client/Server Networks Client Server Workstation Network interface card (NIC) Media NOS Host Node Connectivity device Network Requirements Demo

Elements Common to Client/Server Networks A NIC

Elements Common to Client/Server Networks Segment Backbone Topology Protocol Data packets Addressing Transmission media

Elements Common to Client/Server Networks A LAN backbone

Elements Common to Client/Server Networks Common network topologies Demo

Elements Common to Client/Server Networks Examples of network transmission media

Summary A network is a group of computers and other devices that are connected by some type of transmission media In a peer-to-peer network, every computer can communicate directly with every other computer A client/server network uses a server to enable clients to share data, data storage space, and devices A LAN is confined to a relatively small space, such as a building or office

Summary A MAN is larger than a LAN and connects clients and servers from multiple buildings A WAN connects two or more geographically distinct LANs or MANs Elements common to client/server networks: client, server, workstation, NIC, NOS, host, node, connectivity device, segment, backbone, topology, protocol, data packets, addressing, and transmission media

The End