LAN/WAN Networking: An Overview Chapter 1

Learning Objectives Define and identify the different types of networks Describe the history of LANs and WANs Discuss LAN and WAN integration, including the basic functions of bridges, routers, gateways, and switches Describe network protocol integration methods Explain the preparatory steps of network design

Computer Network System of computers, print devices, and computer software linked by communications cabling or radio waves Typically classified according to: Reach and complexity Protocols and topologies

Network Communication

Network Types Defined Local area networks Metropolitan area networks Wide area networks

Local Area Network (LAN) Series of interconnected computers, printing devices, and other computer equipment that share hardware and software resources Service area usually limited to a given office area, floor, or building

Example of a LAN

Metropolitan Area Network Links multiple LANs in a large city or metropolitan region Typically uses fiber-optic connections

Example of a MAN

Wide Area Network (WAN) Far-reaching system of networks that usually extends over 30 miles and often reaches across states and continents

Network Classification Enterprise network Combination of LANs, MANs, or WANs that provides users with an array of computer and network resources to complete different tasks

Enterprise Network

Identifying a Network Type Communications medium Wire cable, fiber-optic cable, radio waves, microwaves Protocol How networked data is formatted into discrete units How each unit is transmitted and interpreted Topology Physical layout of cable and logical path Network type Private versus public

Events that Led up to LANs and WANs Oersted Morse Undersea cable Pony Express Bell 1900s Transcontinental and transatlantic calls Voice digitization Electronic digital computers Transistors Sputnik Communications satellites ASCII Mass-produced minicomputers

LAN/WAN History: 1960s First WAN Hypertext Use of fiber optics for phone signals Beginning of ARPANET Packets and packet switching UNIX Telecommunications equipment First IMP prototype

LAN/WAN History: 1970s Ethernet ARPANET - 15 sites E-mail Terminal emulation International connections to ARPANET Telecommunications conversion from analog to digital X.25 First wireless gateway Internet Protocol LSI and VLSI chips ICCB

LAN/WAN History: 1980s BITNET IBM’s PC Dial-up modem technology TCP and IP adopted as protocol suite for ARPANET First PC LAN Arrival of Internet Internetwork hosts 5,000 in 1986 100,000 in 1989 “Cyberspace” T-carrier services NFSNET Desktop authoring and multimedia SNMP

LAN/WAN History: 1990s ARPANET retired SS7 technology NSFNET opened to commercial use First cyberbank Internet service providers Over 16 million Internet hosts

LAN/WAN History: 2000s IPv6 used for Internet2 backbone communications Video and radio capability Prices of 1-Gbps devices fall as competition increases

LAN/WAN Integration 1960s-1980s Networks Direct connection to host mainframe using Systems Network Architecture (SNA) communications protocol Networks Allow connections to many devices Enable distributed client/server computing

Using SNA to Directly Connect without a Network

LAN/WAN Integration Becoming more advanced through networking devices Bridges Routers Gateways Switches

Bridges Connect different LANs or LAN segments using the same access method

Routers Connect networks having the same or different access methods and media Forward packets and frames to networks by using a decision-making process based on: Routing table data Discovery of most efficient routes Preprogrammed information from network administrator

Routers

Gateways Enable communications between two different types of networked systems

Gateways

Switches Link network segments Forward and filter frames between segments

Integrating Data Between LANs and WANs Translation Encapsulation LAN emulation (LANE)

Network Design Introduction How networks work in terms of protocols, access methods, and topologies Physical equipment used in LANs and WANs Basic network design principles Using structured wiring and structured networking techniques Designing for multimedia and client/server applications Taking advantage of LAN and WAN device characteristics continued…

Network Design Introduction Assess characteristics of the organization that affect network design Types and locations of computers Software applications and resources required Business patterns High and low network use periods Designing to facilitate troubleshooting Type of security required Anticipated growth

Chapter Summary Basic networking terms and concepts History and evolution of local and wide area networking technologies Different methods of integrating short and long distance information networks How to prepare for designing networks