WORCESTER PUBLIC LIBRA
`IIIIIIII IIII IIIIIIIIII IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIIII IIII mr
`A17807849402
`
`• Everything you need to know about networking PCs
`• Guidelines for configuring a cross-platform network
`• Comprehensive VENDOR LIST and Glossary
`
`/
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, Cover
`
`

`

`This book is printed on acid-free paper. E)
`
`Copyright© 1996 by Academic Press, Inc.
`
`All rights reserved.
`No part of this publication may be reproduced or
`transmitted in any form or by any means, electronic
`or mechanical, including photocopy, recording, or
`any information storage and retrieval system, without
`permission in writing from the publisher.
`
`All brand names and product names mentioned in this book
`are trademarks or registered trademarks of their respective companies.
`
`AP PROFESSIONAL
`1300 Boylston St., Chestnut Hill, MA 02167
`
`An Imprint of ACADEMIC PRESS, INC.
`A Division of HARCO~_RT BRACE & COMPANY
`, ... ,·•"
`United Kingdom Edition published by
`ACADEMIC PRESS LIMITED
`24-28 Oval Road, London NWl 7DX
`
`Tittel, Ed.
`The PC networking handbook / Ed Tittel
`p. cm.
`Includes bibliographical references and index.
`ISBN 0-12-691398-6
`1. Computer networks. I. Title.
`TK5105.5.T62 1995
`004.6'16--dc20
`
`Printed in the United States of America
`96 97 98 99 CP
`9 8 7 6 5 4 3 2 1
`95
`
`95-20918
`CIP
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, Copyright
`
`

`

`--- -
`
`r
`
`CONTENTS
`
`Contents
`
`·v
`
`About the Author
`
`xv
`
`Acknowledgments
`
`xvn
`
`Network Cabling and Media 1
`
`l Network Cabling and Media Types 3
`Cabling Considerations 3 • Coaxial Cable 4 • Fiber-Optic Cable 8 • Twisted-Pair
`Cable
`13 • Wireless Media
`17 • Conclusion
`19
`
`21
`2 Coaxial Cable
`Welcome to the Wonderful World of Coax Cable
`
`21
`
`y
`
`IPR2018-00131
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`

`

`vi
`
`Contents
`
`3 Fiber-Optic Cable
`The Power of Light
`
`33
`33
`
`4 Twisted-Pair Cable
`Twist and Shout
`43
`
`43
`
`5 Wireless Networking
`49
`Wacky for Wireless 4 9 • Top Vendors
`
`54 • Resources: Bibliography & Strategies 5 5
`
`57
`6 Cable Testing and Diagnostic Equipment
`Cabling Catastrophes
`57 • Summary
`61 • Top Vendors
`Strategies
`63
`
`62 • Resources: Bibliography and
`
`7 Cable Layouts
`Topologies
`65
`
`65
`
`II Networking Technologies and Access Methods 73
`
`75
`8 Networking Technologies and Access Methods
`Access Methods 7 6 • Networking Technologies
`79 • Summary
`
`83
`
`85
`9 Ethernet
`86 • Ethernet Frames
`85 • Basic Networking and Ethernet
`Introduction
`l 00 • Building Your
`Cabling Specifications
`95 • Hardware Considerations
`l 0 l • Ethernet Resources: Bibliography and Strategies
`l 02 • The Top Five
`Network
`l 03
`Ethernet Vendors
`
`92 • Ethernet
`
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`

`

`Contents
`
`vii
`
`l O Token Ring
`Token Ring?
`Operation
`
`l 05
`106 • Token Ring Examined
`105 • Origins of the Ring
`110 • Summary
`115 • Bibliography and References
`115
`
`107 • Token Ring in
`
`11 FDDI
`117
`117 • Why FDDI?
`FDDI Defined
`Bibliography and References
`126
`
`118 • FDDI Standards
`
`119 • Summary
`
`126 •
`
`12
`
`ISDN
`127
`129 • End-to-End
`127 • Evolution of ISDN
`127 • ISDN Standards
`ISDN Defined
`ISDN
`133 • Bearer Services
`136 • ISDN Protocols
`138 • Broadband ISDN
`139 •
`14 l
`Summary
`
`143
`13 Asynchronous Tran sf er Mode
`145 • Migration to
`About ATM
`143 • Broadband ISDN
`144 • ATM Transport
`ATM
`149 • ATM on the Market
`151 • Conclusion
`152 • Bibliographies and
`Resources
`15 2
`
`155
`14 More Access, More Transmission
`156 •
`156 • Transmission
`Access
`155 • AR(net
`155 • Broadband lANs
`X.25
`15 7 • Synchronous Optical Network
`15 7 • Switched Multimegabit Dato
`Services
`157 • Frame Relay
`157 • High (Bit Rote) Digital Subscriber Line
`158
`
`Ill Networking Protocols 1 S9
`
`161 ·
`15 Protocols
`16 l • Networking Protocols
`Protocols Defined
`Standards and Stacks
`165
`
`163 • Networking
`
`,i
`'i
`
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`

`

`viii
`
`Contents
`
`17 5
`16 TCP /IP
`17 6 • Common TCP /IP
`175 • What Makes TCP /IP Tick?
`TCP /IP Revealed
`180 • The TCP /IP Architecture
`Terminology
`177 • The Origins of lnterne1working
`Model
`184 • The TCP /IP Breakdown
`188 • Installing TCP /IP
`197 • Administering TCP/
`IP Ne1works
`199 • TCP /IP Sof1ware Vendors
`200 • TCP /IP References
`200
`
`17
`
`203
`IPX/SPX: The NetWare Protocols
`Ne1working for Business
`203 • Bibliography and Resources
`
`223
`
`225
`18 NetBIOS
`226 • Specifically
`225 • NetBIOS: Myths and History
`Ne1work Basic Input/Output System
`Speaking
`226 • The OSI Connection
`231 • NetBIOS and NetBEUI: Bibliography and
`Strategies
`232
`
`235
`19 SNA
`237 • SNA
`236 • SNA History
`235 • OSI ... Again?
`To Read or Not to Read
`239 • SNA vs. the OSI Model
`247 •
`243 • lnterne1working SNA
`Briefing
`Summary
`250 • Bibliography and Resources
`250 • Top Five SNA lnterne1working
`Vendors
`251
`
`253
`20 Apple Talk Protocols
`Apple Philosophy
`253 • Bibliography and Resources
`
`271
`
`273
`21 A Few More Protocols
`27 4 • LAN
`27 4 • OSI
`273 • Xerox Ne1working System
`Digital Ne1work Architecture
`Manager
`275 • Server Message Blocks
`275 • UNIX
`275 • IBM
`276 • Advanced
`Peer-to-Peer Ne1working
`27 6
`
`IPR2018-00131
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`Ex. 1046, p. viii
`
`

`

`Contents
`
`ix
`
`277
`22 Protocol Analyzers
`284 • The
`278 • Network Performance Analysis
`Basic Overview
`277 • The Analyzer
`Security Discussion
`286 • What to Buy
`287 • Top Five Vendors
`288 • Protocol Analyzer
`Resources: Bibliography and Strategies
`290
`
`IV Networking Equipment 293
`
`295
`. 23 The Networking Bestiary
`Connection Equipment
`296 • Servers of Many Flavors
`Peripherals
`297 • Summary
`298
`
`296 • Networked
`
`299
`24 Network Interface Cards
`· 302 • Pieces and Parts of a
`What's in a NI(? Basic Overview
`299 • Touring by Bus
`NI(
`311 • Installation Secrets
`319 • Common NIC-Related Problems
`326 • Buying Tips:
`New or Used, Local or Mail Order?
`330 • NI( Resources: Bibliography and Strategies
`334 •
`The Top Five NI( Vendors
`335
`
`337
`25 Hubs and Concentrators
`Connectivity 101 : Basic Overview
`33 7 • LAN Concentrator Details: What ls a
`Concentrator?
`338 • Hub Details
`339 • Hub and Concentrator Resources: Bibliography and
`Strategies
`355 • Top Five Vendors
`356
`
`359
`26 Routers, Bridges, and Gateways
`365 • Gateways
`Basic Overview
`359 • Bridges
`360 • Routers
`37 4 • Resources: Bibliography and Strategies
`Buy
`37 4 • Top Vendors
`
`372 • What to
`377
`
`379
`27 Servers: An Introduction
`Network Services
`379 • At Your Service
`Summary
`385
`
`379 • Who Needs Servers?
`
`385 •
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. ix
`
`

`

`X
`
`Contents
`
`387
`28 Vanilla File/Print Servers
`388 • File Server
`In The Beginning: Basic Overview
`387 • A look Back
`396 • Factors to
`Components
`388 • Different Types of File Servers
`393 • Print Servers
`Consider When Buying a File Server
`399 • Factors to Consider When Buying a Print
`Server
`400 • Top Four File Server Vendors
`401 • Top Three Print Server Vendors
`Resources: Bibliography and Strategies
`402
`
`401 •
`
`29 Multiprocessing and Special-Purpose Servers
`Overview
`405 • The Power of Symmetry for MP
`Bibliographies and Resources
`415
`
`405
`407 • The Top 5 MP Vendors
`
`412 •
`
`417
`30 Database Servers
`419 • What's a Database Server? 4 21 •
`417 • What's a Database?
`Database History
`Deploying the Workhorse
`426 • What Is Client/Server?
`426 • Back to the
`Future
`427 • Summary
`427 • The Top Five Database Vendors
`427 • Database Servers:
`Bibliography and Strategies
`428 • The Top Five Database Vendors
`429
`
`431
`31 Communications Servers
`440 • How NOS
`433 • Security
`General Communication
`432 • Communications Servers
`Vendors Handle Communications
`440 • Communications Servers That Include Fax
`Capabilities
`441 • Resources: Bibliography and Strategies
`441 • The Top Seven
`Communications Servers Vendors
`44 2
`
`445
`32 Fax Servers
`445 • Fax Server Products
`Technology Overview
`and Strategies
`453 • Top Five Fax Server Vendors
`
`452 • Fax Server Resources: Bibliography
`454
`
`457
`33 Special Services
`Technology Overview
`457 • A Closer Peek at the Technology
`Resources: Bibliography and Strategies
`462 • Top Five Vendors
`
`458 •
`462
`
`IPR2018-00131
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`Ex. 1046, p. x
`
`

`

`Contents
`
`xi
`
`34
`
`465
`Introducing Network Peripherals
`469 •
`The Keys to the Network
`465 • Where There's a CPU, There Goes the Network!
`Novell's Embedded Systems Technology 4 71 • Microsoft's At Work Architecture 4 7 6 •
`Summary
`478 • Bibliography
`479
`
`35
`
`481
`Interfaces
`487 • Integrated Device
`481 • Top SCSI Vendors
`Hardware Interfaces: Basic Overview
`Electronics
`488 • Food for Thought: Future Cereals?
`490 • Bibliography
`492
`
`495
`36 Printers
`501 • Networked
`495 • Different Kinds of Printers
`Anatomy of a Printer: Basic Overview
`Printers
`507 • Installation
`508 • Common Troubleshooting for Printers
`510 • What to
`Buy
`51 l • Top Five Printer Vendors
`512 • Printer Resources: Bibliography and
`Strategies
`513
`
`515
`37 CD-ROM
`518 • Networking
`515 • Details, Details, Details
`Dissection of a CD-ROM: Basic Overview
`CD-ROMs
`533 • What's the Multimedia Wave?
`535 • What Type ofrC Do You
`539 •
`Need?
`536 • Installation
`536 • Troubleshooting Common CD-ROM Problems
`Whatto Buy
`540 • Top Five Vendors
`541 • Top Ten CD-RO Ms
`54 2 • CD-ROM
`Resources: Bibliography and Strategies
`54 2
`
`543
`38 Network Fax/Modem
`545 • Networking Fax
`FAXing Away: Basic Overview
`543 • Details, Details, Details
`Modems
`555 • What Type of PC Will I Need?
`557 • Troubleshooting Fax
`Modems
`561 • What to Buy?
`561 • Top Five Vendors
`563 • Networked Fax Modem
`Resources: Bibliography and Strategies
`563
`
`IPR2018-00131
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`Ex. 1046, p. xi
`
`

`

`xii
`
`Contents
`
`565
`39 Scanners
`572 •
`565 • Different Kinds of Scanners
`Scanning 101: Basic Overview
`Networked Scanners
`579 • The Software Side of the Scanning Story
`580 •
`Installation
`583 • Common Troubleshooting for Scanners
`586 • What to Buy
`Top Five Scanner Vendors
`588 • Sources of Info (Annotated Bibliography)
`589
`
`587 • The
`
`V Network Management S91
`
`40
`
`593
`Introduction to Network and Systems Management
`593 • Explaining
`Basic Network and Systems Terminology
`593 • Understanding Systems
`Networks
`595 • Introducing Network and Systems Management
`598 • The Mixed Blessings
`af Client/Server Technology
`599 • Is Server Management Network or Systems
`Management?
`601 • Summary
`618 • Bibliography
`619
`
`621
`41 Wire Management Tools
`622 • Two Main
`622 • Intelligent Hubs
`Basic Overview
`621 • Network Monitors
`Intelligent Hub Vendors
`626 • The Virtual Network
`627 • The Top Five Vendors
`628 •
`Wiring Management Tools Resources: Bibliography and Strategies
`629
`
`631
`42 Server Management Tools
`633 • The
`632 • What's OutThere?
`Basic Overview
`631 • Why the Need for Tools?
`Top Five Vendors
`639 • Server Management Tools Resources: Bibliography and Strategies
`641
`
`643
`43 Workstation Management Tools
`646 • Future Desktop
`Evolution of Workstation Audits
`643 • Today's Desktop Management
`Management
`657 • The Desktop Management Task Force
`657 • Compatibility with Other
`Standards
`663 • What Does All This Mean?
`663 • Workstation Management Tools:
`Bibliography and Strategies
`664 • Top Five Workstation Management Tools Vendors
`665
`
`IPR2018-00131
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`Ex. 1046, p. xii
`
`

`

`Contents
`
`xiii
`
`667
`44 Management Consoles
`670 • Pulling It All Together
`Easy as l, 2, 3 667 • The Building Blocks
`Three Management Console Vendors
`681 • Management Console Resources:
`Bibliography and Strategies
`682
`
`677 • The Top
`
`A Glossary
`
`685
`
`B Vendor Contact Information
`
`721
`
`C A List of Networking Resources
`
`819
`
`D Accessing Networking Information Online
`
`823
`
`839
`E Locating Vendors and Product Information
`What Else Is Available from Vendors?
`839 • Doing the Contact Thing
`Hierarchy
`844 • Summary
`845
`
`842 • The Contact
`
`Index
`
`847
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. xiii
`
`

`

`chap te r
`
`TCP /IP
`
`TCP /IP REVEALED
`Commissioned by the same benevolent U.S. government that brought us
`the Vietnam war and the P-38 can opener, TCP /IP is designed to be inde(cid:173)
`pendent of hardware considerations, operating systems, network operat(cid:173)
`ing systems, physical transmission links, and other criteria that were once
`stumbling blocks on the path to internetwork communications.
`TCP /IP is a set of protocols that were created specifically to allow devel(cid:173)
`opment of network and internetwork communications on a global scale.
`Although the origins and definition of TCP/ IP date back more than 25
`years, TCP /IP remains the most durable and common set of protocols in
`use in network communications today. TCP /IP supplies extended network
`capability to machines and networks of different types, using many differ(cid:173)
`ent operating systems and communicating using a wide variety of technol(cid:173)
`ogies, which can include local and asynchronous links, packet radio
`transmissions, and satellite links.
`The development of TCP /IP has paralleled the growth of the Internet,
`the most tangible manifestation of the widely publicized and much bally(cid:173)
`hooed "information superhighway." The Department of Defense (DoD)
`helped to create and evaluate TCP /IP, beginning in the late 1960s and
`throughout the 1970s. By 1984 the DoD adopted TCP /IP as its official Inter(cid:173)
`net protocol. Many people believe that TCP /IP' s adoption as an internet(cid:173)
`working standard was the most significant step on the way to creating the
`worldwide internetwork we call the Internet. In this chapter, you'll learn
`
`175
`
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`
`

`

`176
`
`Part Ill • Networking Protocols
`
`about the beginnings of the TCP /IP protocol, why it's been around so long,
`how the TCP /IP protocols interoperate, and the kinls of services and capa(cid:173)
`bilities they provide.
`
`WHAT MAKES TCP /IP TICK?
`One reason for the TCP /IP suite's legendary flexibility is the fact that it was
`not developed as a top-down set of protocols created to structure commu(cid:173)
`nications but as a ground-up set of protocols that has always responded,
`and continues to respond, to available technologies. What this means is
`that the original developers of the TCP/ IP protocol, most of whom are still
`cruising around the Internet, came up with their designs based on current(cid:173)
`ly available technology.
`From its very beginnings the developers of TCP /IP encouraged-and
`continue to do so to this day~user involvement in the development of the
`protocols. As new technologies (like new hardware, software, or commu(cid:173)
`nications links) become available, approved protocols for including them
`can be-and often are-added to the TCP/ IP protocols.
`For TCP /IP, all definitions and descriptions of its protocols and services
`are contained in requests for comment (RFCs). RFCs constitute the collec(cid:173)
`tion of documents that specify and describe what TCP /IP is and what it
`does. RFCs are assigned in numeric order and are referred to by number.
`They may be submitted by anyone who feels that additions or modifica(cid:173)
`tions to the protocols already in use are called for. In this way, additional
`TCP/ IP protocols are developed for new technologies.
`
`® Specs: RFC 1720
`
`The current document that describes the Internet official protocol
`standards is RFC1720. Even though the phrase request for comment
`sounds more like a question to solicit feedback on an idea (which is
`how the bulk of RFCs actually function), standard RFCs have the
`weight of law in the Internet and TCP /IP communities.
`RFCs actually dictate how protocols behave and what functions
`they must perform. Failure to conform to these definitions, especially
`for required or recommended protocols, can cost a vendor the oppor(cid:173)
`tunity of doing business with the United States government and all
`the other bodies and agencies that adhere to its guidelines. Access to
`
`IPR2018-00131
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`Ex. 1046, p. 176
`
`

`

`Sixteen • TCP /IP
`
`177
`
`the RFCs may be obtained from the Internet host ds.internic.net via
`FTP or electronic mail, or via the Word Wide Web at http://
`www.cis.ohio-state.edu/hypertext/ information/ rfc.html.
`
`Next, you'll examine the history of TCP /IP, and how it parallels the his(cid:173)
`tory of computer networking, but first it might be helpful to define some
`common terms from the TCP /IP world.
`
`COMMON TCP /IP TERMINOLOGY
`
`While TCP /IP isn't really all that complicated, it's going to be hard to ex(cid:173)
`plain all of its ins and outs without agreeing on some terminology. All of
`these terms are common in the networking community, but restating them
`here should make sure you know what we're talking about when we use
`them!
`
`Addressing
`In the network world, every device needs an identifying number that is
`unique to that device. Usually these identifiers are made up of some com(cid:173)
`bination of numbers. For network, and internetwork communications to
`occur, each device needs to have this unique numeric ID, or address. For
`purposes of this discussion there are two important types of addressing: IP
`addresses and MAC layer addresses.
`
`IP Addresses
`IP addresses are unique numerical addresses based on a standard scheme
`and assigned by a central governing body. They are used to communicate
`between nodes on an internetwork.
`
`MAC Loyer Addresses
`Media access control addresses are the hardware addresses used by nodes
`on a network to identify and locate one another. They are used to commu(cid:173)
`nicate between nodes on the same wire and are most often built right in to
`the NICs used for network communications. MAC addresses are the lowest
`
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`
`

`

`178
`
`Part Ill • Networking Protocols
`
`level of network identifiers and provide the final links by which informa(cid:173)
`tion is passed from device to device on a network.
`
`Datagram
`A packet that contains data and delivery information is a datagram.
`
`End Nodes
`These are the machines (devices) on a network at which users perform their
`work. Desktop PCs, printers, and file servers connected to a network are all
`examples of end nodes.
`
`Gateway
`A gateway is a machine that connects a network of hosts to another net(cid:173)
`work. On the Internet, gateways function as routers, passing messages
`along until they reach their destination.
`
`Host
`A host is any machine (device) connected to a network or internetwork.
`
`Internet
`Most network schemes are controlled by routers that handle network com(cid:173)
`munications and monitor network activity for the rest of the connected
`nodes. An internet is a set of two or more network routers that are connect(cid:173)
`ed and able to share processing and data.
`
`The Internet
`The formal name for a worldwide matrix of gateways and hosts transfer(cid:173)
`ring and sharing information. This is the specific internetwork constantly
`being referred to in the newspapers and broadcast media. This is by far the
`largest internetwork in the world, connecting universities, military instal(cid:173)
`lations, research facilities, corporations, and much more.
`
`IPR2018-00131
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`Ex. 1046, p. 178
`
`

`

`Sixteen • TCP /IP
`
`179
`
`Network
`A network is any collection of machines or devices connected physically by
`some type of physical transport medium (i.e., wire). Network devices may
`all be on the same wire or they may be connected over a series of wires us(cid:173)
`ing bridges or repeaters.
`
`Node
`A node is any machine (device) connected to a network or internetwork.
`
`Packets
`Information is carried across networks in blocks of information called pack(cid:173)
`ets. Transmission of uniform packets of information allows for many hosts
`on a network to communicate simultaneously over the same transport me(cid:173)
`dium. Packets also contain information about themselves that allow for er(cid:173)
`ror detection and correction across the network. Packets have two parts:
`· the header and the body.
`
`Header
`The header carries information such as the source and destination of a
`packet.
`
`Body
`The body is the raw data carried by a packet or, in many cases, another type
`of (encapsulate) packet that contains its own header and body.
`
`Protocol
`A protocol, in networking, is a set of rules that specifies the formation of
`network packets and sets forth the ways these packets are handled on the
`network. Each protocol is designed to deal with a specific function or col(cid:173)
`lection of functions (see Chapter 15 for a more detailed explanation of this
`all-important networking concept).
`
`IPR2018-00131
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`Ex. 1046, p. 179
`
`

`

`180
`
`Part Ill • Networking Protocols
`
`Routers
`Routers are machines that connect nodes on a network. Routers perform all
`the functions offered by the network operating system and are responsible
`for knowing how the network topology is configured and transferring in(cid:173)
`formation from one part of the network to another.
`Because of its origins and because TCP /IP and internetworking (and the
`Internet itself) are so intertwined, we're going to examine the beginnings of
`computer networking, the origins of TCP/ IP, the development of the TCP/
`IP protocols, and how all these have combined to give us the global inter(cid:173)
`network known to users, TV commentators, politicians, and software ven(cid:173)
`dors worldwide as the Internet.
`
`THE ORIGINS OF INTERNETW0RKING
`
`Today, when millions of computers of all kinds communicate freely across
`a worldwide internetwork of machines and LANs, it's hard to relate to a
`time when computers, both large and small, did all their work in isolation.
`But that's the way it was in the early days of computing.
`The original computers were developed for the U.S. Department of
`Defense during World War II to aid in the war effort. These machines were
`lavishly expensive monstrosities that labored around the clock to solve
`complicated mathematical problems related to artillery targeting, logistics,
`and accounting. They required pretty large teams of engineers, scientists,
`and technicians, for maintenance and operations support. These teams of
`computer "babysitters" all worked more or less in splendid isolation. Any
`sharing of information between these teams happened over the telephone,
`or at the odd meeting or conference, on a more or less as-needed basis.
`Communication between these machines just didn't happen, or it was
`based on a primitive version of "sneakernet," where highly paid techni(cid:173)
`cians lugged crates of punch cards or paper tape from one computer or
`computing center to another.
`It didn't take long for the brain trust at the Department of Defense,
`which was responsible for all these machines, to recognize a real need to tie
`the machines together and eliminate the expense and duplication of effort
`involved in computing as practiced in its most prehistoric form. One par(cid:173)
`ticular agency, the Advanced Research Projects Agency (ARP A), was
`formed inside the Department of Defense with a charter to find an effective
`method to enable computer-to-computer and, ultimately, network-to-net-
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. 180
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`Sixteen • TCP /IP
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`181
`
`work communications. It would serve as the source of funding and inspi(cid:173)
`ration for the efforts that have culminated in the Internet so widely used
`around the world today.
`
`Machine Talk
`The first links between isolated computing machines involved simply
`stringing wire between two or more machines and creating some kind of
`program that would allow them to communicate with each other. The same
`approach worked pretty well for tying peripheral devices like printers,
`storage devices, and any terminals that were required. Of course, the limi(cid:173)
`tations of this approach are obvious. The length of the wire itself physically
`defined the strength of the signal it carried. This method worked fine, up
`to a point, for linking computers in the same room or the same building,
`but wasn't much help when it came to linking machines separated by many
`miles (as was the case with the small number of widely scattered comput(cid:173)
`ers originally acquired by the U.S. government).
`Devices were developed to modulate computer signals into the audible
`tones required for phone transmissions and to demodulate them back into
`computer signals at the other end of the phone transmission. These
`'modems' allowed computers to communicate over phone lines and
`enabled a great leap forward in communication between remote comput(cid:173)
`ing machines and networks. But these early telephone links, or circuits,
`allowed only one machine to talk to one other machine at a time.
`Some method had to be developed to allow telephone circuits to be frag(cid:173)
`mented to allow multiple computers to be networked. Various approaches
`were tried. Multiplexing, or the decomposition down of a single circuit into
`multiple but limited channels, was the most common method. Even the
`success of multiplexing was clouded by the fact that it depended on break(cid:173)
`ing down the already limited bandwidth of a telephone line into even
`smaller "pipes," thus limiting the amount of traffic on the line.
`
`Packet Switching
`Around the end of the 1960s a method of transmission was developed that
`allowed more efficient communications, called packet switching This meth(cid:173)
`od, which is still used today, involves breaking down arbitrarily long mes(cid:173)
`sages into equal-sized packages of information and choosing the best route
`available for shipping them from a sender to one or more receivers, rather
`than using a predefined channel or band.
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. 181
`
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`

`182
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`Part Ill • Networking Protocols
`
`The development of packet switching environments provided the step
`necessary to enable the networking and internetworking world that we
`now know. All that is necessary in this environment is that packets be
`properly labeled when a message is disassembled in preparation for ship(cid:173)
`ping and that these labels can be clearly read on delivery to permit proper
`reassembly of the pieces into their original format and layout.
`In a packet-switched environment, the links between computers are called
`lines, and the computers where lines come together are called nodes. Comput(cid:173)
`ers add a special set of tags to each packet during assembly, including a
`sender and receiver address, a sequence or ID number, and some flavor of
`quality-control information to ensure the accuracy of the transmission. Indi(cid:173)
`vidual packets can be sent using any available route, or line, in any sequence,
`as long as the receiving node has the ability to translate the addressing and
`reassembly information of each packet. This type of communication is called
`a packet switched network, because packets of information are constantly being
`switched from one line to another by the connected nodes as they forward
`information between sender and receiver.
`Packet switched networks allow many machines to communicate simul(cid:173)
`taneously over a single, common transmission medium because the packet
`labels keep the individual transmissions distinct as they are routed
`between the interlinked nodes. This lets multiple users share the same net(cid:173)
`work and makes all receivers at least theoretically available to all senders.
`
`The ARPAnet
`In the late 1960s, ARPA provided the funding for a number of universities
`where Department of Defense research was ongoing to set up the first in(cid:173)
`ternetwork based on packet switching network. The idea was to link com(cid:173)
`puters of different types-that is, to interconnect machines made by more
`than one manufacturer-and to provide a. broad range of capabilities
`across this network. These capabilities included remote access to other
`computers on the network, and the exchange of files and sharing of periph(cid:173)
`eral resources including things like printers and storage devices. This net(cid:173)
`work came to be known as the ARP Anet or more simply ARP Anet.
`ARP Anet used a special set of communications rules, called the network
`control protocol (NCP), to handle its network traffic. Specially pro(cid:173)
`grammed computers called interface message processors (IMPs) were
`developed and installed to handle the packet-switching duties that this net(cid:173)
`work required. By late 1969, the ARPAnet was successfully up and run(cid:173)
`ning, linking computers in California and Utah. The early success of
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. 182
`
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`Sixteen • TCP /IP
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`183
`
`ARP Anet caused an explosion of interest in networking and internetwork(cid:173)
`ing and quickened the pace of the development of networking technolo(cid:173)
`gies. Within three years of ARPAnet's introduction, several new
`internetworks were set up around the United States, and links to the inter(cid:173)
`national computing community were also established.
`
`The Origins of TCP/IP
`The rapid proliferation of ARP Anet-derived technologies soon pointed out
`fundamental weaknesses in its internetworking capabilities. NCP, the pro(cid:173)
`tocol developed to handle messaging across the ARP Anet, was too depen(cid:173)
`dent on the characteristics of the original ARP Anet itself to accommodate
`some of the new and radically different networking and transmission tech(cid:173)
`nologies that were coming on-line around the world. The initial investment
`in IMPs, which were required by ARP Anet for packet switching duties,
`also restricted internetworking access from the growing world networking
`community.
`In 1972, ARP A, now renamed the Defense Advanced Research Projects
`Administration (DARPA), formed the InterNetworking Working Group
`(INWG). Vincent Cerf, the chairman of the group (and one of the original
`developers of ARP Anet), and his team began work to create what would
`become an internationally agreed-upon set of standard networking proto(cid:173)
`cols for a networking environment to be designed to replace the original
`ARP Anet implementation.
`Even then, it was widely believed that a new suite of protocols would be
`necessary to support the proliferation of new and radically different net(cid:173)
`working technologies. Based on experience with the ARP Anet, this new
`design also had well-defined parameters: it needed. to provide mail ser(cid:173)
`vices, to enable mail delivery and reception between remote hosts; it
`needed to provide terminal services to allow remote terminals to connect
`to and execute commands on a remote host; and it needed to provide file
`transfer services to enable files to be moved easily and efficiently from host
`to host. In answer to all of these needs, Cerf's INWG team created the nec(cid:173)
`essary specifications and developed a new suite of protocols and related
`services, which were named the transmission control protocol/internet protocol
`(TCP /IP).
`
`IPR2018-00131
`Riot Games, Inc. v. PalTalk Holdings, Inc.
`Ex. 1046, p. 183
`
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`184
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`Part Ill • Networking Protocols
`
`THE TCP /IP ARCHITECTURE MODEL
`
`The OSI reference model for network architecture is covered in detail in
`Chapter 15, so in this chapter, you'll have a chance to examine a layered
`model of the TCP /IP protocol suite, as you learn how this model corre(cid:173)
`sponds to the corresponding OSI layers. The OSI reference model demon(cid:173)
`strates the activities necessary at each level of networking activity to
`implement working networks and categorizes the operations required for
`successful networking, based on the layers it introduces to break up net(cid:173)
`working into a sequence of logically related tasks. Since the OSI reference
`model was created after the development of TCP/ IP it does not share the
`same exact view of how networking should be subdivided into logically
`disjoint tasks. Nevertheless, mapping the TCP /IP suite to the OSI reference
`model should help you obtain a better understanding of TCP /IP imple(cid:173)
`mentation.
`
`The Open Systems In