TCPIP_01TOC.fm Page i Thursday, June 9, 2005 11:16 AM THE TCP/IP GUIDE by Charles M. Kozierok SECTION I TCP/IP OVERVIEW AND BACKGROUND INFORMATION PART I-1 NETWORKING FUNDAMENTALS 1 NETWORKING INTRODUCTION, CHARACTERISTICS, AND TYPES 5 Introduction to Networking ................................................................................................6 What Is Networking? .................................................................................................6 The Advantages and Benefits of Networking .................................................................7 The Disadvantages and Costs of Networking ................................................................9 Fundamental Network Characteristics ...............................................................................10 Networking Layers, Models, and Architectures ............................................................10 Protocols: What Are They, Anyway? ..........................................................................11 Circuit-Switching and Packet-Switching Networks ........................................................13 Connection-Oriented and Connectionless Protocols ......................................................16 Messages: Packets, Frames, Datagrams, and Cells .............................................................17 Message Formatting: Headers, Payloads, and Footers .................................................19 Message Addressing and Transmission Methods: Unicast, Broadcast, and Multicast ........20 Network Structural Models and Client-Server and Peer-to-Peer Networking ............................23 Types and Sizes of Networks ...........................................................................................26 Segments, Networks, Subnetworks, and Internetworks ........................................................27 The Internet, Intranets, and Extranets .................................................................................30 2 NETWORK PERFORMANCE ISSUES AND CONCEPTS 33 Putting Network Performance in Perspective .......................................................................34 Balancing Network Performance with Key Nonperformance Characteristics ..........................35 Performance Measurements: Speed, Bandwidth, Throughput, and Latency ............................36 Speed ....................................................................................................................36 Bandwidth ..............................................................................................................37 Throughput .............................................................................................................37 Latency ..................................................................................................................37 Summary of Performance Measurements ....................................................................38 Understanding Performance Measurement Units .................................................................39 Bits and Bytes .........................................................................................................39 Baud .....................................................................................................................40 Theoretical and Real-World Throughput, and Factors Affecting Network Performance .............41 Normal Network Overhead ......................................................................................41 External Performance Limiters ....................................................................................42 Network Configuration Problems ...............................................................................42 Asymmetry .............................................................................................................43 Simplex, Full-Duplex, and Half-Duplex Operation ...............................................................43 Simplex Operation ..................................................................................................44 Half-Duplex Operation .............................................................................................44 Full-Duplex Operation ..............................................................................................44 Quality of Service (QoS) .................................................................................................45 TCPIP_01TOC.fm Page ii Thursday, June 9, 2005 11:16 AM 3 NETWORK STANDARDS AND STANDARDS ORGANIZATIONS 47 Proprietary, Open, and De Facto Standards ......................................................................48 Proprietary Standards ..............................................................................................48 Open Standards .....................................................................................................49 De Facto Standards .................................................................................................50 Networking Standards ....................................................................................................50 International Networking Standards Organizations ............................................................51 Networking Industry Groups ............................................................................................53 Internet Standards Organizations (ISOC, IAB, IESG, IETF, IRSG, and IRTF) ............................54 Internet Registration Authorities and Registries (IANA, ICANN, APNIC, ARIN, LACNIC, and RIPE NCC) ......................................57 Internet Centralized Registration Authorities ................................................................57 Modern Hierarchy of Registration Authorities ..............................................................58 Internet Standards and the Request for Comment (RFC) Process ............................................59 RFC Categories .......................................................................................................60 The Internet Standardization Process ..........................................................................60 4 A REVIEW OF DATA REPRESENTATION AND THE MATHEMATICS OF COMPUTING 63 Binary Information and Representation: Bits, Bytes, Nibbles, Octets, and Characters ..............64 Binary Information ...................................................................................................64 Binary Information Representation and Groups ...........................................................65 Byte Versus Octet ....................................................................................................66 Decimal, Binary, Octal, and Hexadecimal Numbers ...........................................................67 Binary Numbers and Their Decimal Equivalents ...........................................................67 Making Binary Numbers Easier to Use by Grouping Bits ..............................................68 Octal Numbers .......................................................................................................68 Hexadecimal Numbers ............................................................................................69 Decimal, Binary, Octal, and Hexadecimal Number Conversion ...........................................70 Binary, Octal, and Hexadecimal Conversions .............................................................70 Conversion from Binary, Octal, or Hexadecimal to Decimal .........................................71 Conversion from Decimal to Binary, Octal or Hexadecimal ..........................................72 Binary, Octal, and Hexadecimal Arithmetic .......................................................................73 Binary Arithmetic .....................................................................................................74 Octal and Hexadecimal Arithmetic ............................................................................74 Boolean Logic and Logical Functions ................................................................................75 Boolean Logical Functions ........................................................................................75 Combining Boolean Expressions ...............................................................................77 Bit Masking (Setting, Clearing, and Inverting) Using Boolean Logical Functions ......................77 Setting Groups of Bits with OR ..................................................................................78 Clearing Bits with AND ............................................................................................78 Inverting Bits with XOR .............................................................................................79 ii Contents in Detail TCPIP_01TOC.fm Page iii Thursday, June 9, 2005 11:16 AM PART I-2 THE OPEN SYSTEM INTERCONNECTION (OSI) REFERENCE MODEL 5 GENERAL OSI REFERENCE MODEL ISSUES AND CONCEPTS 83 History of the OSI Reference Model ..................................................................................84 General Reference Model Issues ......................................................................................85 The Benefits of Networking Models ...........................................................................85 Why Understanding the OSI Reference Model Is Important to You .................................86 How to Use the OSI Reference Model ........................................................................87