Contentsstore.westnetlearning.com/mkt/catalog/toc/PCN_TOC.pdfContents iii Lesson 4 Network...
Transcript of Contentsstore.westnetlearning.com/mkt/catalog/toc/PCN_TOC.pdfContents iii Lesson 4 Network...
Contents
Preface ........................................................................... xxvii
Prerequisites .................................................................................xxviiWho Should Study This Course? .................................................xxviiKey Topics ...................................................................................xxviiiCourse Objectives ........................................................................xxviiiCTP Exam Information .................................................................xxix
Exam Objectives .....................................................................xxixHow Do I Use This Course? ......................................................... xxxv
Real-World Scenarios ...........................................................xxxviPedagogy ..............................................................................xxxviKey Terms .............................................................................xxxvi
Resources Available in Instructor-Led Settings ...........................xxxviWhy Choose WestNet? ..............................................................xxxvii
Introduction .................................................................. xxxix
Course Overview .........................................................................xxxix
Module 1Physical Communication Infrastructure ..............................1
Lesson 1Communication and Signals ..................................................3
Analog and Digital Transmission .......................................................4Analog Transmission ...................................................................4Modulation ..................................................................................5Analog Bandwidth ......................................................................6Digital (Baseband) Transmission .................................................6Digital Signals Over Analog Links ...............................................7Digital Bandwidth .......................................................................8
One-Way or Two-Way Transmission .................................................8Signal Timing ..............................................................................8
Different Signals, Different Media .....................................................9Communication Standards ................................................................9
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Physical Signaling Standards Organizations .............................10ITU ......................................................................................10IEEE .....................................................................................10EIA and TIA ........................................................................11ANSI ....................................................................................11ISO ......................................................................................11AT&T and Bell Labs ............................................................12
Internet Standards Organizations .............................................12NSF .....................................................................................12IETF .....................................................................................13ISOC ...................................................................................14IAB ......................................................................................15IESG ....................................................................................15IRTF ....................................................................................15IANA and ICANN ...............................................................16
IP Address Assignment ..............................................................18W3C ....................................................................................18
Review Questions .............................................................................19
Lesson 2Internal Computer Components: CPU, I/O, Memory, and NICs ..............................................................23
CPU ..................................................................................................23I/O ....................................................................................................24
Video Display ............................................................................26Memory ............................................................................................26NICs ..................................................................................................27
Different Networks, Different NICs ..........................................27Each NIC is Unique ...................................................................28NIC Connectivity in a PC .........................................................28Summary of NIC Characteristics ...............................................29
Review Questions .............................................................................30
Lesson 3Software ..............................................................................32
Programs and Processes ....................................................................32Master/Slave ..............................................................................33Peer-to-Peer ...............................................................................33Client/Server ..............................................................................33
Client/Server Advantages ...................................................34Independent Computing Architecture ..............................34
Hosts ..........................................................................................34Application Software ........................................................................34Operating Systems ............................................................................35Device Drivers ..................................................................................35Network Management Software .......................................................36Review Questions .............................................................................37
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Lesson 4Network Topologies ............................................................39
Types of Networks ............................................................................39Bus Topology ....................................................................................40Star Topology ...................................................................................41Ring Topologies ................................................................................42
Ring ...........................................................................................42Star Ring ....................................................................................43
Wide Area Topologies ......................................................................45Full Mesh ...................................................................................45Partial Mesh ...............................................................................46Network Cloud ..........................................................................46
Advantages of Cloud Networks ..........................................47Hybrid Topologies ............................................................................48Logical and Physical Topologies ......................................................49
Physical Star, Logical Bus ..........................................................49Physical Star, Logical Ring ........................................................50
Review Questions .............................................................................51
Lesson 5Copper Cable ......................................................................54
Transmission Basics ..........................................................................54Voltage Buildup .........................................................................55Timing Synchronization ...........................................................56Signal Strength ..........................................................................56
Transmission Problems and Characteristics ....................................56Electrical Noise ..........................................................................57Crosstalk ....................................................................................57Attenuation ...............................................................................58Capacitance ...............................................................................58DC Resistance ............................................................................58Impedance .................................................................................58Continuity and Polarity ............................................................59Cable Length .............................................................................59
Limiting Noise and Crosstalk ...........................................................59Coaxial Cable ...................................................................................60
10Base5 ......................................................................................6110Base2 ......................................................................................62
The 5/4/3 Rule ....................................................................64Summary of Coaxial Wiring Rules .....................................64Other Coaxial Cabling Characteristics ..............................64
Twisted Pair Cable ............................................................................65UTP Cable ..................................................................................66STP Cable ...................................................................................68
10BaseT Star Topology .....................................................................69Other Twisted Pair Cabling Characteristics ..............................72
IBM Cable Types ..............................................................................72Type 1 ........................................................................................72
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Type 2 ........................................................................................72Type 3 ........................................................................................73Type 5 ........................................................................................73Type 6 ........................................................................................73Type 8 ........................................................................................73Type 9 ........................................................................................73
Review Questions .............................................................................74
Lesson 6Fiber Optic Cable .................................................................77
Fiber Communication Systems ........................................................78Transmitter ................................................................................78Receiver .....................................................................................79
Fiber Optic Cable Construction .......................................................79Fiber Optic Dimensions ...................................................................80Types of Fiber Optic Cable ...............................................................81
Multimode Fiber ........................................................................81Step-Index Fiber .................................................................82Graded-Index Fiber ............................................................82
Single-Mode Fiber ......................................................................82Installing Fiber Optic Cable .............................................................83Review Questions .............................................................................84
Lesson 7Cable and Equipment Installation ........................................85
Structured Wiring Systems ...............................................................86Cable Convergence ...................................................................86Hub-Based Distributed Star Topology .......................................86Industry-Wide Standards ..........................................................87
The TIA/EIA-568 Standard ...............................................................88Structured Wiring Subsystems .........................................................88
Building Entrance ......................................................................89What Termination Means ..................................................89Punch-Down Blocks ...........................................................90Patch Panels .......................................................................91
Equipment Room ......................................................................92Vertical (Backbone) Cabling .....................................................92Wiring Closets ...........................................................................93Horizontal Wiring .....................................................................93Work Area ..................................................................................93Universal Wiring Subsystems ....................................................94Cabling Distances ......................................................................95Cabling Types ............................................................................95
General Cable Installation Guidelines .............................................96Equipment Installation Standards ...................................................97
NEC ...........................................................................................97NEBS ..........................................................................................98
Review Questions ...........................................................................100
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Lesson 8Cables and Connectors ......................................................102
Small UTP Cables ...........................................................................103RJ-45 Connectors ....................................................................103
Patch Cables and Crossover Cables ...............................................104Crossover Cables .....................................................................104Patch Cables ............................................................................105Connector Pinout Patterns .....................................................105
Building and Testing Small UTP Cables .........................................10725-Pair UTP Cables .........................................................................107
Identifying Wire Pairs in a 25-Pair Cable ................................107Quad Wire Cables ..........................................................................109
“Tip and Ring” Circuits ...........................................................109Circuit Polarity and Voltage ....................................................110RJ-11/RJ-14 Connectors ..........................................................110
Serial Cable Connections ...............................................................111RS-232 ......................................................................................111RS-422 ......................................................................................112V.35 .........................................................................................113
Review Questions ...........................................................................115Summary ...........................................................................117Quiz ..................................................................................119
Module 2A Layered System of Data Protocols ...............................127
Lesson 1Protocols and the OSI Model .............................................129
What is a Protocol? ........................................................................129A Simple Machine Protocol .....................................................130Protocol Headers .....................................................................131
Layers of Protocols and Services ....................................................131A Layered Communication System ........................................131
Encapsulation ...................................................................132Decapsulation ...................................................................132
Why Layers? ............................................................................132Layers of Computer Protocols .................................................133Layers of Services .....................................................................133Peer Processes ..........................................................................133
How Layers Work Together ...........................................................134Encapsulation and Protocol Headers ......................................134
Header Fields ....................................................................135Segmentation ...................................................................135
Decapsulation ..........................................................................135Reassembly ..............................................................................136
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The OSI Model ...............................................................................136The OSI Open Standard ..........................................................137The OSI Stack ..........................................................................137
Review Questions ...........................................................................139
Lesson 2The Physical Layer .............................................................142
Hardware Devices ...........................................................................142A Stream of Bits ..............................................................................143Minimal Error Detection ................................................................143Example: Manchester Encoding ....................................................144Review Questions ...........................................................................145
Lesson 3The Data Link Layer ...........................................................146
Frames Across a Link ......................................................................146Packets Within Frames ............................................................147Frame Addressing ....................................................................147
Data Link Layer Services ................................................................147On the Transmitting Node ......................................................147On the Receiving Node ...........................................................148
Error Detection and Correction: FCS .............................................149Data Link Layer Protocols ..............................................................150One Link, One Frame .....................................................................150Review Questions ...........................................................................152
Lesson 4The Network Layer ............................................................154
Packets Across Networks ................................................................154Network Layer Addresses vs. Data Link Layer Addresses ...............155
Data Link Addresses: Physical ..........................................155Network Addresses: Logical ..............................................156
Packet Routing ...............................................................................157Basic Data Transmission Methods .................................................158
Circuit Switching ....................................................................158Packet Switching .....................................................................159Connection-Oriented Networks ..............................................160Connectionless Networks .......................................................161
Network Layer Services ..................................................................162Network Layer Protocols ................................................................162Review Questions ...........................................................................163
Lesson 5The Transport Layer ...........................................................165
End-to-End Communication .........................................................166Transport Layer Services .................................................................167
Addressing ...............................................................................167Connection Management .......................................................167Flow Control and Buffering ....................................................168
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Multiplexing and Parallelization ............................................168Reliable and Sequenced Delivery ............................................169Service Quality Management ..................................................170
Transport Layer Protocols ..............................................................170Review Questions ...........................................................................171
Lesson 6The Session Layer ..............................................................173
Electronic Conversations ...............................................................173Establishing, Conducting, and Ending a Session ..........................174Dialogs ............................................................................................175
Token Passing ..........................................................................175Activity Management ..............................................................176Sync Points ..............................................................................176
Session Layer Protocols ..................................................................177Review Questions ...........................................................................178
Lesson 7The Presentation Layer .......................................................179
Computer Numbering ....................................................................179The Binary Numbering System ...............................................180The Hexadecimal Numbering System .....................................181
Presentation Layer Services ............................................................183Data Representation ................................................................183
Data Security ....................................................................184Data Compression ...................................................................185
Review Questions ...........................................................................187
Lesson 8The Application Layer ........................................................189
Common Application Layer Programs ..........................................190E-Mail ......................................................................................190USENET Newsgroups ...............................................................191File Transfer and Access ..........................................................191Virtual Terminals ....................................................................192Web Browsers and Servers .......................................................193
Review Questions ...........................................................................194Summary ...........................................................................195Quiz ..................................................................................197
Module 3Data Networking Protocols .............................................201
Lesson 1 LAN Data Link Protocols ...................................................202
A Short History of the LAN ............................................................202When Mainframes Ruled the Earth ........................................202Enter the PC ............................................................................203
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New Data Link Protocols ................................................................203LLC Sublayer ...........................................................................203MAC Sublayer ..........................................................................204
The IEEE 802 Suite of LAN Protocols .............................................205Review Questions ...........................................................................207
Lesson 2Ethernet ............................................................................208
Ethernet Medium Access Control ..................................................208CSMA/CD ................................................................................210Ethernet Frame Addressing .....................................................211
Advantages and Disadvantages of Ethernet ...................................211Ethernet Configurations ................................................................212Fast Ethernet ..................................................................................213
Fast Ethernet Over Twisted Pair ..............................................213Fast Ethernet Over Fiber ..........................................................214Mixed Ethernet Networks .......................................................214
Gigabit Ethernet .............................................................................215Gigabit Ethernet Cabling and Distance Specifications ...........217
Fiber Cabling Specifications .............................................218Copper Cabling Specifications .........................................220
Review Questions ...........................................................................221
Lesson 3Token Ring and FDDI .........................................................222
Token Ring Medium Access Control .............................................222Types of Token-Passing Networks ..................................................223
Advantages of Token Ring ......................................................224Disadvantages of Token Ring ..................................................224
Token Ring Configurations ............................................................225FDDI ...............................................................................................227
Dual Channels .........................................................................228ETR and Multiple Messages .....................................................228Synchronous Traffic ................................................................229
Token Bus .......................................................................................229Review Questions ...........................................................................230
Lesson 4Point-to-Point WAN Services ..............................................233
Common Point-to-Point Services ..................................................234POTS Analog Connections .............................................................234
Modems ...................................................................................234Dial-Up Lines ...........................................................................236Leased Lines ............................................................................236PPP ...........................................................................................237
Zero Bit Insertion .............................................................237DSL .................................................................................................238
How DSL Works ......................................................................240DSL Physical Requirements .....................................................240
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Cable Modems ................................................................................241Cable Modem Configuration ..................................................242Shared Bandwidth ...................................................................242
Security .............................................................................243T-Carriers and E-Carriers ................................................................243
T1 Bandwidth ..........................................................................243DS Hierarchy ...........................................................................244FT1 ...........................................................................................245Customer Premises Equipment for T-Carriers ........................246Timing T-Carrier Circuits ........................................................247
The Carrier Interface ........................................................247The Local Network Interface ............................................248Preventing Clocking Problems .........................................249
ISDN ...............................................................................................249How ISDN Works ....................................................................249ISDN-BRI ..................................................................................249ISDN-PRI ..................................................................................251Channel Bonding ....................................................................252H Channels ..............................................................................252
SONET ............................................................................................253SONET Rings ...........................................................................254
Review Questions ...........................................................................255
Lesson 5Switched WAN Services .....................................................258
Circuits and Virtual Circuits ..........................................................259PVCs and SVCs ........................................................................260SVC Information Transfer .......................................................262
Types of Switched Services .............................................................263X.25 ................................................................................................263Frame Relay ....................................................................................264
Frame Relay Characteristics ....................................................267Frame Relay Implementation ..................................................267Local Management Interface ..................................................268
ATM ................................................................................................268Transfer Modes ........................................................................269ATM Characteristics ................................................................270
SMDS ..............................................................................................272SMDS Protocols .......................................................................272Advantages and Disadvantages ...............................................272
The Internet ...................................................................................272Internet Structure ....................................................................273Internet, Intranet, and Extranet .............................................273VPNs ........................................................................................274
Private vs. Public ............................................................................274Review Questions ...........................................................................275
Summary ...........................................................................277Quiz ..................................................................................278
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Module 4Data Networking Components .......................................285
Lesson 1Repeaters and Hubs ...........................................................287
Repeaters ........................................................................................287Hubs ...............................................................................................289Token Ring MAUs ..........................................................................290Token Ring Repeaters .....................................................................290Ethernet Collision Domains ..........................................................291
Hub-to-Hub Connectivity .......................................................292Stackable Hubs ...............................................................................294Chassis Hubs ..................................................................................295Review Questions ...........................................................................296
Lesson 2Bridges ..............................................................................299
Bridge Functionality .......................................................................299Traffic Isolation .......................................................................300
Types of Bridges .............................................................................302Bridge Algorithms ..........................................................................302
Transparent Bridging ..............................................................302Filtering and Forwarding ..................................................303Learning ...........................................................................304An Example of Learning, Filtering, and Forwarding .......304Active Loops .....................................................................306Spanning Tree Protocol ....................................................307
Source Route Bridging .............................................................309How Source Route Bridging Works ..................................310Internetworking with Source Route Bridges ....................311
Comparing Source Route Bridging to Transparent Bridging ..311Centralized vs. Distributed Function ...............................311Types of Networks Supported ..........................................312Overhead Traffic ...............................................................312Administration .................................................................312Complexity and Cost .......................................................312Flexibility ..........................................................................313
Source Route Transparent Bridging ........................................313Translation Bridging ...............................................................313
Review Questions ...........................................................................314
Lesson 3Switches ............................................................................319
Switch Functionality ......................................................................320Forwarding and Filtering .........................................................321Learning ..................................................................................322Switches as Bandwidth Multipliers .........................................322
Ethernet Switch Operation ............................................................323Speed vs. Accuracy ..................................................................323
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Port Buffering ..........................................................................324Port Switching to Eliminate Collisions ...................................324
Combining Switches With Hubs and Bridges ................................325Token Ring Switches ......................................................................327
Backbone and Workgroup Token Ring Switching ..................327Review Questions ...........................................................................332
Lesson 4Routers and VLANs ............................................................337
Introduction to Routers .................................................................338How Routers Work ..................................................................339Multiprotocol Routing ............................................................340
How Routers Move Packets Between Networks .............................340Routers Rebuild Frames ...........................................................341Internet Routers ......................................................................342Broadcast Domains .................................................................342
Routers for Broadcast Containment ................................344Router Advantages and Disadvantages ...................................344
Routing Tables ................................................................................345Static and Dynamic Routing ...................................................345Determining the Best Path ......................................................346
Related Devices ...............................................................................349Brouters ...................................................................................349Layer 3 Switches ......................................................................349
Comparing L3 Switches and Routers ...............................350Examples of Layer 3 Switching Techniques .....................350
Protocol Converters .......................................................................350VLANs .............................................................................................352
Switched VLANs ......................................................................353Routed VLANs .........................................................................354VLANs for Broadcast Containment ........................................355The Future of VLANs ...............................................................356
Review Questions ...........................................................................357
Lesson 5Network Servers ................................................................361
LAN Services ...................................................................................361File Servers ......................................................................................362
File Access Attributes ...............................................................363Synchronization ......................................................................364Semaphores (Flags) ..................................................................364Caching on File Servers ...........................................................364
Database Servers .............................................................................365Print Servers ...................................................................................365Web Servers ....................................................................................367
Web Caching ...........................................................................368Cache Servers ...................................................................369“Faster” or “Fresher” ........................................................369
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Application Servers .........................................................................369Application Platforms .............................................................370Types of Applications ..............................................................370
RAS (Communication Servers) .......................................................371RAS Platforms ..........................................................................371
Review Questions ...........................................................................372Summary ...........................................................................374Quiz ..................................................................................376
Module 5TCP/IP Protocols and Services .........................................383
Lesson 1The TCP/IP Protocol Suite ..................................................385
TCP/IP Protocol Layers and the OSI Model ...................................385Network Interface Layer Protocols ..........................................386Internetwork Layer Protocols ..................................................386Transport Layer Protocols .......................................................387Application Layer Protocols ....................................................388
Communication Using TCP/IP ......................................................389Application Layer ....................................................................389Transport Layer .......................................................................389Network Layer .........................................................................390Network Interface Layer ..........................................................391Destination Station .................................................................391
Review Questions ...........................................................................392
Lesson 2IP .......................................................................................394
Overview of IP ................................................................................394Best-Effort Service ....................................................................395Multiplexing Protocols ............................................................396
IP Packet Encapsulation .................................................................396IP Version 6 ....................................................................................397
IPv6 Address Format ................................................................398IPv4 Compatibility ..................................................................398
ICMP ...............................................................................................399ICMP’s Purpose and Limits .....................................................399Encapsulation ..........................................................................399Message Types .........................................................................400
Destination Unreachable (3) ............................................401Source Quench (4) ............................................................401Redirect (5) .......................................................................402Echo Request (8) and Echo Reply (0) ...............................402Time Exceeded (11) ..........................................................402Parameter Problem (12) ....................................................402Timestamp Request (13) and Timestamp Reply (14) .......402
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Information Request (15) and Information Reply (16) ...403Address Mask Request (17) and Address Mask Reply (18) 403
Review Questions ...........................................................................404
Lesson 3Address Resolution: ARP and RARP .....................................407
ARP .................................................................................................407ARP's Operation .......................................................................407
ARP Request ......................................................................408ARP Response ...................................................................409ARP Features .....................................................................410
Proxy ARP ................................................................................411Frame Encapsulation ......................................................................411RARP ...............................................................................................412Review Questions ...........................................................................413
Lesson 4UDP and TCP .....................................................................415
Features Common to Both UDP and TCP .....................................415Demultiplexing Based on Port Number ..................................416Types of Port Numbers ............................................................418Well-Known Port Numbers .....................................................418Ports and Addressing ...............................................................420
UDP ................................................................................................420TCP .................................................................................................421
Basic Data Transfer ..................................................................421Reliable and Sequenced Packet Delivery .................................421Flow Control ...........................................................................422Multiplexing and Demultiplexing ..........................................422Connection Establishment .....................................................422
Sockets ..............................................................................423Review Questions ...........................................................................424
Lesson 5Internet Addressing ...........................................................427
IP Addresses ....................................................................................427Class A Address ........................................................................428Class B Address ........................................................................429Class C Address .......................................................................429Class D Address .......................................................................429Class E Address ........................................................................430
Dotted Decimal Notation ...............................................................430Addressing Rules ............................................................................431Sample Network Using Class A Address Format ............................431Getting an IP Network Address ......................................................432
Public Networks ......................................................................433Private Networks .....................................................................433
Review Questions ...........................................................................435
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Lesson 6Subnetting Fundamentals ..................................................437
The Value of Subnetting ................................................................437The IP Address Crisis ...............................................................438Why Multiple Network Segments? .........................................438
Interconnection of TCP/IP Networks .............................................438The Network Mask .........................................................................440Creating Subnets ............................................................................441IP Prefixes .......................................................................................442IP Broadcast Addresses ...................................................................442
Limited Broadcast ....................................................................443Directed Broadcast ..................................................................443
CIDR ...............................................................................................443Large Routing Tables ...............................................................444The Proposed Solution ............................................................445
How CIDR Works .............................................................445Reduction of Routing Table Entries ........................................447
Review Questions ...........................................................................448
Lesson 7IP Routing ..........................................................................450
Overview of Internet Architecture .................................................450Router Characteristics .............................................................452
Direct Routing ................................................................................452Indirect Routing .............................................................................453
Static Routing ..........................................................................455Default Routing .......................................................................455Dynamic Routing ....................................................................456
Building the Routing Table ............................................................456Sample Network Routing Table ..............................................458
How Routers Move Packets Between Networks .............................460Host A ......................................................................................461Packet on Network 128.1.0.0 ..................................................461Packet on Network 128.2.0.0 ..................................................461Packet on Network 128.3.0.0 ..................................................462Packet on Network 128.4.0.0 ..................................................463Host B ......................................................................................464
Review Question ............................................................................465
Lesson 8IP Address Management: BOOTP, DHCP, and NAT ............467
Bootstrap Protocol (BOOTP) ..........................................................467BOOTP Operation ...................................................................468
Client BOOTREQUEST Message .......................................468Server BOOTREPLY Message ............................................469
Client BOOTREPLY Message Receipt ......................................470The BOOTP Relay Agent .........................................................470
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TFTP ................................................................................................471DHCP ..............................................................................................471
DHCP Address Allocation Mechanisms ..................................472DHCP Operation .....................................................................473
DHCP Services ..................................................................473How DHCP Clients Obtain Configuration Information .474DHCP Client Lease Renewal ............................................476
DHCP Relay Agents .................................................................476IP Address Conflicts ................................................................477
NAT ................................................................................................478What is Address Reuse? ...........................................................478A NAT Overview ......................................................................478NAT Address Spaces .................................................................479IP Address Translation .............................................................479
Static Address Translation ................................................480Dynamic Address Translation ..........................................480
Enhanced Network Security ....................................................481Masquerading/NAPT ...............................................................482
How NAPT Works ............................................................482NAPT for More Security ...................................................485
Review Questions ...........................................................................487
Lesson 9IP Name Resolution: HOSTS, DNS, and WINS ....................490
HOSTS File ......................................................................................491DNS ................................................................................................492
Hierarchical Structure .............................................................492TLDs .................................................................................493Distributed Authority .......................................................494Second-Level Subdomains ................................................494Zones ................................................................................495
Domain Names ........................................................................495Types of Domain Names ..................................................496Domain Name Syntax ......................................................496
DNS Client/Server Operation ..................................................497Name Servers ....................................................................497Resolvers ...........................................................................497Querying the Name Database ..........................................498
NetBIOS Name Resolution .............................................................498Broadcasts ................................................................................499LMHOSTS file ..........................................................................499WINS .......................................................................................499
Name Resolution Challenges .........................................................500Incompatible Systems .............................................................500Static vs. Dynamic ...................................................................500
Review Questions ...........................................................................501Summary ...........................................................................503Quiz ..................................................................................505
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Module 6The Public Telephone Network .......................................513
Lesson 1Local Exchange Components .............................................515
The Telephone System Hierarchy ..................................................516Class 5 Central Office: The Local Exchange ...........................517Class 4 Central Office ..............................................................519Tandem Central Offices ..........................................................520Class 1 Office ...........................................................................522
Class 5 Central Office Components ..............................................523Switching and Routing ............................................................523Semipermanent Circuit Connections .....................................524IXC POP ..................................................................................525Billing ......................................................................................525Customer Premises ..................................................................525
Local Exchange Calling Options ....................................................526LEC Does It All ........................................................................526CLEC Serves as Reseller ...........................................................526CLECs Switch and ILECs Wire ................................................526CLEC Does It All ......................................................................527
Review Questions ...........................................................................528
Lesson 2Central Office Switching ....................................................530
The Talking Path ............................................................................530Digital Switches ..............................................................................532How a Call is Made ........................................................................532
Call Setup ................................................................................533Call Connection ......................................................................533Call Completion ......................................................................536Ending the Call .......................................................................536
Telephone Numbering System .......................................................536NANP .......................................................................................536International Numbering Plan ................................................537Global Numbering Plan ..........................................................538
Special Area Codes .........................................................................538Special NXX Codes ..................................................................539
Special Information: 555 ..................................................539Hearing-Impaired Services: 800-855 ................................539
Service Codes ...........................................................................539Follow-Me: 500 ........................................................................539International: 700 ...................................................................539Toll-Free: 800, 888, 877, 866 ...................................................540Premium: 900 ..........................................................................540
Review Questions ...........................................................................541
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Lesson 3Trunks, Lines, and Loops ....................................................542
Telecommunications Terms ...........................................................543Loops ..............................................................................................544Lines ...............................................................................................544Trunks .............................................................................................544
Trunk Direction .......................................................................545Trunk Capacity ........................................................................545Analog or Digital Transmission ..............................................545
Converting Analog Voice to Digital .................................545Multiplexing .....................................................................547Digital Channels ..............................................................547
Special Access Trunks .....................................................................548Tie Lines ..................................................................................548Private Lines ............................................................................549FX ............................................................................................549
Foreign Exchange Interfaces ............................................550Ring Down ..............................................................................551Trunk Pricing ...........................................................................551
Review Questions ...........................................................................553
Lesson 4Analog Voice Impairments .................................................555
Analog Transmission Impairments ................................................555Noise ........................................................................................556Echo .........................................................................................556Crosstalk ..................................................................................557Delay ........................................................................................558Loss (Attenuation) ...................................................................558
Analog Signal Filtering: A Special Case ..........................................558Review Questions ...........................................................................561
Lesson 5Small Office Telephone Equipment ....................................562
Key Systems ....................................................................................562Key System Components ........................................................562Cordless Key Systems ..............................................................564Limitations of Key Systems .....................................................565Hybrid Systems ........................................................................565
Central Office Exchange (Centrex) ................................................565How Centrex Works ................................................................566Centrex Benefits ......................................................................567Technical Requirements for Centrex ......................................567
Distance From CO Switch ................................................567Allocation of Call Paths ...................................................568CPE ...................................................................................568
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Principles of Converged Networks: VoIP, Voice, and Data
Centrex Features ......................................................................568Centrex vs. PBX .......................................................................569Combining Centrex with Other Switching Systems ..............569
Review Questions ...........................................................................570
Lesson 6Private Branch Exchange ....................................................573
PBX Components ...........................................................................573Trunks ......................................................................................574Extension Lines .......................................................................575Equipment Cabinet .................................................................575Telephones and Attendant Console .......................................576Administrative Terminal .........................................................577
Making a Call on a PBX .................................................................577Call Routing ...................................................................................577Supplementary PBX Features .........................................................578
DID ..........................................................................................579DISA .........................................................................................580UDP .........................................................................................580
Station Set Features ........................................................................581Attendant Console Services ...........................................................582Call Accounting .............................................................................583
Authorization Codes ...............................................................584Account Codes ........................................................................584
Administration and Management Reports ....................................585Call Detail Reports ..................................................................585Test Reports .............................................................................585Busy-Hour Studies ...................................................................585
PBX Enhancements ........................................................................586Voice Response ........................................................................586Voice Recognition ...................................................................586Call Following .........................................................................586ACD .........................................................................................587Other Auxiliary Equipment ....................................................587Paging Equipment ...................................................................587CMS .........................................................................................588
Review Questions ...........................................................................589
Lesson 7Voice Mail Systems ............................................................592
Voice Mail Features ........................................................................592Voice Mail/PBX Integration ....................................................593Design Factors .........................................................................594Unified Messaging ...................................................................595Broadcasting ............................................................................595Voice Mail Security .................................................................595
Automated Attendants ...................................................................597Review Questions ...........................................................................598
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Lesson 8Signaling Basics .................................................................600
Supervisory Signals .........................................................................601Loop Start ................................................................................602Ground Start ............................................................................603E&M .........................................................................................605Emulated Tie Trunks ...............................................................605Wink Start ...............................................................................606Digital Signaling ......................................................................606
T1 Framing and A,B,C, and D bits ...................................607E1 Framing and Signaling ................................................609
Address Signals ...............................................................................610Dial Pulse Signaling .................................................................610Dual Tone Multifrequency (Touch Tone) Signaling ...............611
Alerting Signals ..............................................................................612Control Signals ...............................................................................612In-Band vs. Out-of-Band Signaling ................................................612Review Questions ...........................................................................613
Lesson 9SS7 ....................................................................................616
The Need for SS7 ............................................................................616SS7 Integrated Services ...................................................................617SS7 Architecture .............................................................................618
SSP ...........................................................................................618STP ...........................................................................................618SCP ..........................................................................................619SS7 Network Links ...................................................................619
SS7 Call Signaling Steps .................................................................620LNP ..........................................................................................621SS7 Protocol Stack ...................................................................621
MTP ..................................................................................622ISUP and TUP ...................................................................622SCCP .................................................................................623TCAP .................................................................................623
Review Questions ...........................................................................624
Lesson 10ISDN .................................................................................626
ISDN Protocols ...............................................................................626DSS1 ................................................................................................627
DSS1 Protocols .........................................................................628Physical Layer: I.430, I.431 ..............................................628Data Link Layer Call Setup: LAPD ...................................628Network Layer Call Control, I.451/Q.931 .......................629Network Layer Packet-Switching, X.25 ............................629
I.451/Q.931 Signaling .............................................................629
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Principles of Converged Networks: VoIP, Voice, and Data
QSIG ...............................................................................................630DCE and DTE .................................................................................632
DTE-to-DCE Protocols .............................................................632Layer Upon Layer ....................................................................633
ISDN CPE ........................................................................................634Supported Switch Types ..........................................................636
Review Questions ...........................................................................638Summary ...........................................................................640Quiz ..................................................................................642
Module 7Convergence ....................................................................651
Lesson 1Packet Telephony ..............................................................653
The Present: Separate Networks .....................................................654How Packet Telephony Works .......................................................655
Making the Shift ......................................................................656Packet Telephony Standards ..........................................................658Internet Telephony Categories ......................................................659
Computer-to-Computer ..........................................................659Computer-to-Telephone .........................................................660Telephone-to-Telephone .........................................................661Web-to-Call Center Systems ...................................................662
Telephony Gateway .......................................................................662Dedicated Servers with Voice Cards ........................................663Router or Access Concentrator with Voice Cards ...................664
Packet Telephony Products ............................................................664Toll Bypass Products ................................................................665LAN-Based PBX Systems ..........................................................665The UnPBX ..............................................................................665
Review Questions ...........................................................................667
Lesson 2General QoS Concepts ......................................................668
Network Requirements for Convergence .......................................668Converged Network Architecture ..................................................669
A Hybrid Approach to Convergence .......................................669Parallel WAN Paths for QoS ....................................................670Application-Level QoS .............................................................671
Voice Quality ..................................................................................671The QoS Parameters .......................................................................672
Bandwidth ...............................................................................673Throughput .............................................................................673Delay ........................................................................................674
Encoding, Decoding, and Compression ..........................675Packetization ....................................................................675
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Contents
Jitter .........................................................................................676Jitter Buffers ......................................................................676Measuring Jitter ................................................................677
Wander ....................................................................................678Packet Loss ..............................................................................678Availability ..............................................................................679Security ....................................................................................680
Review Questions ...........................................................................681
Lesson 3Overview of Telecommunications Standards ......................684
ITU-T Protocols ..............................................................................684Commercial Telecommunica-tions Standards ........................685Codecs .....................................................................................685Multimedia Call Control and Signaling .................................686
H.32x–Multimedia over Data Networks ..........................687Call Setup, Signaling, and Control Protocols ..................687Supplementary Packet Telephony Services ......................689
ISDN Protocols ........................................................................689ISDN Switching and Signaling Protocols ................................690Terminal Protocols ..................................................................690Data Communications over the Voice Network .....................691Packet Data Network Protocols ...............................................691
IEEE .................................................................................................692ANSI ................................................................................................692Telcordia .........................................................................................693EIA and TIA ....................................................................................694IETF .................................................................................................695
RFCs .........................................................................................695Internet Standards ...................................................................695BCP ..........................................................................................695
Review Questions ...........................................................................697
Lesson 4Admission Control and Traffic Shaping ..............................699
Admission Control .........................................................................699Traffic Shaping ...............................................................................701
Traffic Smoothing ...................................................................702Traffic Burst Shaping ...............................................................703
Network Admission Policies ...........................................................703Admission Control and Traffic Shaping Applications ...................705Review Questions ...........................................................................707
Lesson 5Traffic Prioritization ............................................................709
802.1Q VLAN Standard ..................................................................709The VLAN Tag .........................................................................709802.1Q as an Architecture .......................................................711
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Principles of Converged Networks: VoIP, Voice, and Data
802.1Q Protocols .....................................................................711802.1p Traffic Prioritization Standard ...........................................712
Priority Tags and Traffic Classes .............................................712How 802.1p Prioritizes Traffic .................................................713Mapping 802.1p Traffic Prioritization to IP
and ATM Networks ..............................................................714Review Questions ...........................................................................715
Lesson 6H.323 Standard for Packet Multimedia ..............................718
Overview of the H.323 Standard ....................................................718Version 1: Videophone ...........................................................719Version 2: Packet-Based Multimedia .......................................719Version 3: Under Development ..............................................719
Other Standards of the H.323 Family ............................................719Fundamental H.323 Network Components ..................................720
Terminals .................................................................................720MCUs .......................................................................................720Gateways .................................................................................721Gatekeepers .............................................................................722
MGCP .............................................................................................723MGCP Network Components .................................................723
MG ....................................................................................724MGC .................................................................................725
The H.323 Protocols and Their Effect on Voice Stream QoS .........725H.323 Protocols .......................................................................725Audio Codecs ..........................................................................726
Silence Suppression ..........................................................727G.711 Companding Algorithms ......................................727MOS ..................................................................................729Audio Codec Delays .........................................................729DSPs ..................................................................................730DSP Delays ........................................................................730
RTP ..........................................................................................730Time Stamping .................................................................731Sequencing .......................................................................731
RTCP ........................................................................................732RAS: H.225 ...............................................................................732Call Signaling: H.225 ..............................................................732Control Signaling: H.245 ........................................................732H.323 Protocol Limitations .....................................................733Document Conferencing: T.120 Series ...................................733
Integration with the Digital PSTN .................................................733ISDN/VoIP Integration ............................................................733Adding SS7 to VoIP .................................................................734
Network Infrastructure Requirements ...........................................736Review Questions ...........................................................................737
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Lesson 7H.323 Call Processing ........................................................740
H.323 Call Progression Phases .......................................................740Gatekeeper Discovery and Registration: H.225 RAS ...............741Call Setup and Signaling: H.225 .............................................742Control Signaling: H.245 ........................................................745Call Termination: H.245/H.225 ..............................................747
H.323v2 fastStart ............................................................................748SIP ...................................................................................................750SS7 to ITSP Call Progression ...........................................................750Review Questions ...........................................................................753
Lesson 8Session Initiation Protocol ..................................................756
SIP ...................................................................................................756SIP Messages ...................................................................................758
Request Messages ....................................................................758SIP Addresses ....................................................................759Request Message Format ..................................................759
Response Messages ..................................................................760Response Message Format ................................................761
SIP Servers .......................................................................................761Proxy .......................................................................................761Redirect ....................................................................................762Registrar ...................................................................................762
SIP Clients ......................................................................................762SDP .................................................................................................762Creating a SIP Session ....................................................................764Activities ........................................................................................766
Lesson 9Approaches to IP Network QoS .........................................768
IP Header Features ..........................................................................768ToS Field ..................................................................................768IP Precedence ...........................................................................769
DiffServ ...........................................................................................769DSCP Code Points ...................................................................769PHB ..........................................................................................770
Standard PHBs ..................................................................770Custom PHBs ....................................................................771
DiffServ Domains ....................................................................771IntServ ............................................................................................771
RSVP ........................................................................................772CBQ ................................................................................................772COPS ...............................................................................................773MPLS ...............................................................................................775Policy Routing ................................................................................777PQ ...................................................................................................777
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Principles of Converged Networks: VoIP, Voice, and Data
RED .................................................................................................777Traffic Shaping ...............................................................................777WFQ ...............................................................................................778WRED .............................................................................................778Review Questions ...........................................................................779
Summary ...........................................................................781Quiz ..................................................................................783
Module 8Troubleshooting ..............................................................791
Lesson 1Common Network Testing Tools .......................................793
Winipcfg, IPconfig, and IFconfig ...................................................794Winipcfg Operation ................................................................794IPconfig Operation ..................................................................796IFconfig Operation ..................................................................798
Ping ................................................................................................799Command Line Switches ........................................................800
Tracert or Traceroute ......................................................................802Command Line Switches ........................................................804
Netstat ............................................................................................804Command Line Switches ........................................................805Repeating a Netstat Command ...............................................806
ARP .................................................................................................806Command Line Switches ........................................................807Changing the ARP Cache ........................................................808
Common IP Configuration Errors .................................................809Duplicate IP Addresses ............................................................809Default Gateway Addressing Errors .........................................810Address/Subnet Mismatch ......................................................811
Protocol Analyzers (Sniffers) ..........................................................812Components of a LAN Protocol Analyzer ...............................812Protocol Analyzer Traces .........................................................813
BERT ...............................................................................................814Testing Physical Media ...................................................................815
Copper Cables .........................................................................815Tone Generator and Probe ...............................................815Media Tester/Certifier ......................................................816Hub, Switch, and Router Indicators .................................818Lineman’s Test Set (Butt Set) ............................................819
Optical Fiber ............................................................................820Wireless LANs ..........................................................................820
Review Questions ..........................................................................821
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Lesson 2A Step-by-Step Method .....................................................824
Troubleshooting Steps ....................................................................8241. Establish the Symptoms ......................................................8252. Identify the Affected Area ...................................................8263. Establish What Has Changed ..............................................8264. Select the Most Probable Cause ..........................................8275. Implement a Solution .........................................................8276. Test the Result .....................................................................8277. Recognize the Potential Effects of the Solution ..................8288. Document the Solution ......................................................828
Review Questions ..........................................................................829
Lesson 3Troubleshooting a Wiring Problem ....................................831
The Problem ...................................................................................831Establish the Symptoms ..........................................................831Identify the Affected Area .......................................................832Establish What Has Changed ..................................................832Select the Most Probable Cause ..............................................832Implement a Solution .............................................................832Test the Result .........................................................................833Recognize the Potential Effects of the Solution ......................833Document the Solution ..........................................................833
Review Questions ...........................................................................834
Lesson 4Converged Network Failure Points .....................................836
Potential Network Failure Points ...................................................836Converged Network To PSTN Interface ..................................837
Admission Errors ..............................................................837Echo and Noise .................................................................838
The LAN ..................................................................................840Protocol Overhead ...........................................................840Percent of Frame Overhead ..............................................841Actual Codec Bandwidth Required ..................................841The Effect of Protocol Overhead on VoIP Networks .......843IP Multicast Traffic ...........................................................843Network Performance ......................................................845
The WAN .................................................................................847WAN Routing and Reliability ..........................................847Backup Paths ....................................................................847Load Sharing ....................................................................850
Review Questions ..........................................................................852
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Lesson 5A Converged Network Troubleshooting Example ...............855
A Network Problem Example .........................................................855Initial Testing ..........................................................................856Digging Deeper ........................................................................857The Fix .....................................................................................859
Review Questions ...........................................................................861Summary ...........................................................................863Quiz ..................................................................................864
Course Quiz ......................................................................871
Index ................................................................................895
Glossary ............................................................................919
Notes ................................................................................955
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