Contents Introduction to Networking Introduction to Networking Preface...i Key Topics...i Course Objectives...ii Pedagogical Features...ii Learning Objectives, Unit Summaries, Discussion Questions, and Activities/Exercises...ii Key Terms...iii Supplements...iii Advancing Your Level of Technical Expertise...iii Why Choose WestNet?...iv Introduction... xix What is a Network?...xix Why Study Networking?... xx Unit 1 Computers and Software in Networks...1 Devices on Networks...5 Desktop Computers: PCs and Workstations...6 Mid-Range Computers and Servers...6 Mainframe Computers... 7 PDAs... 7 Peripheral Devices...8 Internetworking Devices...8 Activities... 9 v
Introduction to Networking Internal Computer Components: CPU, I/O, Memory, and NICs...11 CPU...11 I/O...12 Video Display...15 Memory...16 NICs...18 Different Networks, Different NICs...18 Each NIC is Unique... 19 Activities... 20 Software...22 Programs and Processes...23 Master/Slave Communication...23 Peer-to-Peer Communication... 24 Client/Server Communication...26 Peers, Servers, and Hosts... 28 Application Software...28 Network Applications... 29 OSs...30 Two Important Points... 31 GUIs... 31 Basic OS Features... 31 Networking Features in OSs...32 Device Drivers...33 Network Management Software... 33 Network Security Utilities... 34 Network Management Tools... 35 Remote Access Services... 35 Backup and Recovery Utilities...35 Activities... 36 Lesson 4 Popular OSs...40 Microsoft Windows...40 Windows Desktop OSs...40 Windows NT... 41 Windows 2000...42 Embedded OSs... 43 Novell NetWare...44 UNIX...45 Linux...46 Mac OS... 47 Activities... 48 vi
Contents Unit 2 Carrier Signals, Cable Types, and Network Topologies...55 Communication and Signals...61 Analog and Digital Transmission... 62 Analog Transmission... 62 Modulation...63 Analog Bandwidth...63 Digital (Baseband) Transmission... 64 Digital Signals Over Analog Links... 65 Digital Bandwidth... 66 One-Way or Two-Way Transmission... 66 Signal Timing...67 Signaling Standards...67 ITU... 68 IEEE...68 EIA and TIA... 69 ANSI... 69 ISO... 69 Different Signals, Different Media... 70 Activities... 71 Network Topologies...73 Types of Networks...74 Bus Topology... 74 Star Topology... 76 Ring Topologies...77 Ring... 77 Star Ring...78 Wide Area Topologies...79 Mesh...80 Network Cloud...81 Advantages of Cloud Networks... 82 Network Backbone... 83 Hybrid Topologies, Internetworks, and Enterprise Networks... 86 Logical and Physical Topologies...87 Physical Star, Logical Bus...87 Physical Star, Logical Ring...88 Activities... 89 Copper Cable...93 Coaxial Cable... 94 10Base5...95 10Base2...95 vii
Introduction to Networking viii Twisted Pair Cable...97 UTP Cable...97 10BaseT Star Topology...99 STP Cable... 101 IBM Cable Types...102 ScTP... 103 NEC...103 Activities... 104 Lesson 4 Fiber Optic Cable...105 Fiber Communication Systems...106 Transmitter...106 Receiver... 107 Fiber Optic Cable Construction... 107 Fiber Optic Dimensions... 108 Types of Fiber Optic Cable... 109 Multimode Fiber... 109 Step-Index Fiber...110 Graded-Index Fiber... 110 Single-Mode Fiber... 111 Installing Fiber Optic Cable... 111 Activities... 113 Lesson 5 Wireless Transmission...114 How Wireless Transmission Works...114 The Electromagnetic Spectrum...116 Competition for the Finite RF Spectrum... 118 Wireless Networking Applications... 119 Point-to-Point Microwave Systems...119 Satellites...120 GEO Satellites...121 LEO Satellites... 121 Cellular Systems and PCS... 121 Wireless LANs... 122 Licensed Microwave LANs...123 Nonlicensed Spread Spectrum LANs... 123 Short-Range Infrared Transmission... 125 Wireless LAN Comparison... 125 Mobile Computing...126 Activities... 127 Lesson 6 Overview of a Structured Cable Plant...129 Structured Wiring Systems... 130 Cable Convergence... 130 Hub-Based Distributed Star Topology... 130 Industry-Wide Standards...131
Contents The EIA/TIA-568 Standard... 132 Structured Wiring Subsystems... 133 Building Entrance...134 Punch-Down Blocks...134 Patch Panels...136 Equipment Room...137 Vertical (Backbone) Cabling... 137 Wiring Closets... 138 Horizontal Wiring... 138 Work Area...138 Universal Wiring Subsystems... 139 Cabling Distances... 139 Cabling Types... 140 Vertical (Backbone) Cabling... 140 Horizontal Cabling...140 Activities... 141 Unit 3 Computer Protocols and Services...153 Protocols...156 What is a Protocol?...156 Human Protocols... 158 Computer Protocols... 159 A Simple Machine Protocol... 159 Protocol Headers... 160 Activities... 161 Layers of Protocols and Services...163 A Layered Communication System... 163 Why Layers?... 165 Layers of Computer Protocols...166 Layers of Services... 166 Peer Processes... 167 Differences between Protocol Layers... 169 Meaning vs. Signaling... 169 Logical vs. Physical...170 End-to-End vs. Point-to-Point... 170 How Layers Work Together... 170 Encapsulation and Protocol Headers...171 Decapsulation...172 Reassembly...173 Activities... 174 ix
Introduction to Networking Communicating Across a Network...176 Making a Local Request for Data... 176 Configuring the Client Computer... 177 Requesting Data from a Drive Across a Network... 178 Activities... 180 Unit 4 The OSI Model...187 Introduction to the OSI Model...193 The OSI Open Standard... 194 The OSI Stack... 195 Activities... 196 The Physical Layer...197 Hardware Devices... 197 A Stream of Bits...198 Minimal Error Detection...198 Example: Manchester Encoding...199 Activities... 200 The Data Link Layer...201 Frames Across a Link...201 Packets Within Frames...201 Frame Addressing...202 Data Link Layer Services...202 On the Transmitting Node...202 On the Receiving Node... 203 Error Detection and Correction: FCS... 203 Data Link Layer Protocols...204 One Link, One Frame... 204 Activities... 206 Lesson 4 The Network Layer...208 Packets Across Networks...208 Network Layer Addresses vs. Data Link Layer Addresses... 209 Packet Routing... 210 Basic Data Transmission Methods... 211 Circuit Switching...211 Packet Switching... 213 Connection- Oriented Networks... 213 Connectionless Networks... 214 x
Contents Network Layer Services...215 Network Layer Protocols...215 Activities... 216 Lesson 5 The Transport Layer...218 End-to-End Communication... 219 Transport Layer Services... 220 Addressing... 220 Connection Management... 221 Flow Control and Buffering...221 Multiplexing and Parallelization... 221 Reliable and Sequenced Delivery...222 Service Quality Management...223 Transport Layer Protocols...223 Activities... 224 Lesson 6 The Session Layer...226 Electronic Conversations... 226 Establishing, Conducting, and Ending a Session...227 Dialogs...228 Token Passing...229 Activity Management...229 Sync Points...230 Session Layer Protocols...230 Activities... 231 Lesson 7 The Presentation Layer...232 Computer Numbering...232 The Binary Numbering System... 233 The Hexadecimal Numbering System... 234 Presentation Layer Services...235 Data Representation...236 Data Compression... 240 Activities... 242 Lesson 8 The Application Layer...244 Common Application Layer Programs...245 E-Mail...246 USENET Newsgroups... 246 File Transfer and Access...247 Virtual Terminals...248 Web Browsers and Servers... 249 Activities... 251 xi
Introduction to Networking Unit 5 LANs...259 LAN Data Link Protocols...263 A Short History of the LAN...263 When Mainframes Ruled the Earth...263 Enter the PC...264 New Data Link Protocols...264 LLC Sublayer... 265 MAC Sublayer...265 The IEEE 802 Suite of LAN Protocols... 266 Activities... 268 Ethernet...269 Ethernet Medium Access Control...270 CSMA/CD...271 Advantages of Ethernet...272 Disadvantages of Ethernet... 272 Ethernet Configurations...273 Fast Ethernet...274 Gigabit Ethernet...274 Activities... 276 Token Ring and FDDI...277 Token Ring Medium Access Control... 277 Types of Token-Passing Networks...278 Advantages of Token Ring... 279 Disadvantages of Token Ring... 279 Token Ring Configurations...280 FDDI... 282 Dual Channels... 283 ETR and Multiple Messages... 283 Synchronous Traffic...284 Activities... 285 Lesson 4 Wireless LANs...288 Wireless Protocols...288 Wireless at the Physical Layer... 288 Wireless at the Data Link Layer...289 CSMA/CA... 289 802.11 Wireless Standards... 291 Wireless LAN Configurations... 292 All Wireless LAN...292 xii
Contents Wireless Links Between LANs... 292 Mobile Nodes...293 WPANs and Bluetooth... 294 Activities... 295 Lesson 5 LAN Software Architectures...296 NOSs and LAN Architectures... 296 NetBIOS and NetBEUI...298 Novell NetWare...298 NetWare Protocol Layers... 299 AppleTalk... 300 Shift to Open Standards...300 AppleTalk Phase II Protocol Layers... 301 Cross-Platform Communication... 302 Microsoft Windows NT...302 UNIX and TCP/IP... 304 Common Ground: TCP/IP... 307 Activities... 308 Lesson 6 Information Flow Between Client and Server...309 Protocols and Layers...309 SMB...309 Information Flow and Format... 310 Client Asks Server to Open the File...311 Server Informs Client That the File is Open... 312 Client Asks Server to Read the File...313 Server Reads the File and Transmits the Contents to the Client...314 Client Asks Server to Close the File... 315 Server Informs Client That the File is Closed... 316 Activities... 317 Unit 6 Network Components...325 Repeaters and Hubs...329 Repeaters...329 Hubs... 332 Token Ring MAUs... 333 Token Ring Repeaters... 334 Ethernet Collision Domains...334 Stackable Hubs... 337 Chassis Hubs...338 Activities... 339 xiii
Introduction to Networking Bridges...342 Bridge Functionality... 342 Traffic Isolation... 344 Types of Bridges... 346 Activities... 347 Switches...349 Switch Functionality...349 Traffic Isolation with Switches... 353 Activities... 354 Lesson 4 Routers...357 Router Functionality...357 Multiprotocol Routing... 359 How Routers Move Packets Between Networks... 360 Routers Rebuild Frames... 361 Internet Routers...362 Broadcast Domains...362 Router Advantages and Disadvantages... 364 Activities... 365 Lesson 5 Gateways...367 Types of Gateways...367 Gateways and Remote Access...369 Activities... 370 Unit 7 WANs...377 Point-to-Point WAN Services...382 Common Point-to-Point Services...383 POTS Analog Connections... 383 Modems... 384 Dial-Up Lines... 385 Leased Lines...386 DSL... 386 T-Carriers and E-Carriers...388 T1 Bandwidth...389 DS Hierarchy... 389 FT1... 390 Customer Premise Equipment for T-Carriers... 391 xiv
Contents ISDN... 392 How ISDN Works...392 BRI... 393 PRI... 394 Channel Bonding...395 SONET...395 SONET Rings... 397 Activities... 398 Switched WAN Services...401 Types of Switched Services... 402 X.25...402 Frame Relay...403 Frame Relay Characteristics...406 Frame Relay Implementation...407 ATM...407 The Development of ATM... 409 Transfer Modes...409 ATM Characteristics...410 The Internet... 411 Internet Structure...412 Internet, Intranet, and Extranet... 412 VPNs...413 Activities... 414 Choosing WAN Products and Services...416 The Many Trade-Offs of WAN Design... 416 Cost...418 Performance... 419 Comparing File Transfer Times...421 Bits vs. Bytes...421 Signaling Overhead... 422 Activities... 423 Unit 8 Integrating the Course Elements...433 Building a Small Peer-to-Peer Network...438 What You Will Need... 438 Overview of the Process... 439 Connect the Cables... 439 Set Up Client for Microsoft Networks... 440 xv
Introduction to Networking Network and Transport Layers: Bind Protocols to Each NIC...442 Network and Transport Layers: Configure TCP/IP... 444 Assign IP Addresses and Subnet Masks... 446 Upper Layers: Configure Workgroup and Resource Sharing... 447 Virus Prevention and Detection... 449 Activities... 451 Expanding the Small Network...454 Servers and NOSs...455 File Servers... 456 Database Servers...456 Print Servers... 456 RASs... 458 Web Servers... 459 Traffic Isolation...459 Adding a Switched Backbone...461 Wireless Bridges... 462 Activities... 463 Connecting Networks...468 Routers and Traffic Isolation...468 LAN-to-LAN Connectivity... 470 Connecting to the Internet...471 Home Dial-Up Access...471 SLIP...472 PPP... 473 Business Internet Access...473 Activities... 476 Lesson 4 Data Flow Across Networks...477 Common Network Configuration... 478 Information Flow on a Hub... 478 Information Flow Across a Switched Backbone... 479 Information Flow Across a WAN... 481 DNS...483 Activities... 484 Course Quiz...491 Glossary...501 Index...515 xvi