NETWORKING KEITH W. ROSS. Polytechnic Institute of NYU. Addison-Wesley

Transcription

1 COMPUTER FIFTH EDITION NETWORKING JAMES F. KUROSE University of Massachusetts, Amherst KEITH W. ROSS Polytechnic Institute of NYU Addison-Wesley New York Boston San Francisco London Toronto Sydney Tokyo Singapore Madrid Mexico City Munich Paris Cape Town Hong Kong Montreal

2 Table of Contents Chapter 1 Computer Networks and the Internet What Is the Internet? A Nuts-and-Bolts Description A Services Description What Is a Protocol? The Network Edge Client and Server Programs Access Networks Physical Media The Network Core Circuit Switching and Packet Switching How Do Packets Make Their Way Through Packet-Switched Networks? ISPs and Internet Backbones Delay, Loss, and Throughput in Packet-Switched Networks Overview of Delay in Packet-Switched Networks Queuing Delay and Packet Loss End-to-End Delay Throughput in Computer Networks Protocol Layers and Their Service Models Layered Architecture Messages, Segments, Datagrams, and Frames Networks Under Attack History of Computer Networking and the Internet The Development of Packet Switching: Proprietary Networks and Internetworking: A Proliferation of Networks: The Internet Explosion: The 1990s Recent Developments Summary 68 Road-Mapping This Book 69 XVII

3 xviii Table of Contents Homework Problems and Questions 70 Problems 72 Discussion Questions 79 Wireshark Lab 80 Interview: Leonard Kleinrock 82 Chapter 2 Application Layer Principles of Network Applications Network Application Architectures Processes Communicating Transport Services Available to Applications Transport Services Provided by the Internet Application-Layer Protocols Network Applications Covered in This Book The Web and HTTP Overview of HTTP Non-Persistent and Persistent Connections HTTP Message Format User-Server Interaction: Cookies Web Caching The Conditional GET File Transfer: FTP FTP Commands and Replies Electronic Mail in the Internet SMTP Comparison with HTTP Mail Message Formats Mail Access Protocols DNS The Internet's Directory Service Services Provided by DNS Overview of How DNS Works DNS Records and Messages Peer-to-Peer Applications P2P File Distribution Distributed Hash Tables (DHTs) Case Study: P2P Internet Telephony with Skype Socket Programming with TCP S ocket Programming with TCP An Example Client-Server Application in Java Socket Programming with UDP Summary 178

4 Table of Contents xix Homework Problems and Questions 179 Problems 181 Discussion Questions 189 Socket Programming Assignments 190 Wireshark Labs 192 Interview: Bram Cohen 193 Chapter 3 Transport Layer Introduction and Transport-Layer Services Relationship Between Transport and Network Layers Overview of the Transport Layer in the Internet Multiplexing and Demultiplexing Connectionless Transport: UDP UDP Segment Structure UDP Checksum Principles of Reliable Data Transfer Building a Reliable Data Transfer Protocol Pipelined Reliable Data Transfer Protocols Go-Back-N (GBN) Selective Repeat (SR) Connection-Oriented Transport: TCP The TCP Connection TCP Segment Structure Round-Trip Time Estimation and Timeout Reliable Data Transfer Flow Control TCP Connection Management Principles of Congestion Control The Causes and the Costs of Congestion Approaches to Congestion Control Network-Assisted Congestion-Control Example: ATM ABR Congestion Control TCP Congestion Control Fairness Summary 294 Homework Problems and Questions 296 Problems 299 Discussion Questions 310 Programming Assignments 311 Wireshark Lab: Exploring TCP 312 Interview: Sally Floyd 313

5 xx Table of Contents Chapter 4 The Network Layer Introduction Forwarding and Routing Network Service Models Virtual Circuit and Datagram Networks Virtual-Circuit Networks Datagram Networks Origins of VC and Datagram Networks What's Inside a Router? Input Ports Switching Fabric Output Ports Where Does Queuing Occur? The Internet Protocol (IP): Forwarding and Addressing in the Internet Datagram Format IPv4 Addressing Internet Control Message Protocol (ICMP) IPv A Brief Foray into IP Security Routing Algorithms The Link-State (LS) Routing Algorithm The Distance-Vector (DV) Routing Algorithm Hierarchical Routing Routing in the Internet Intra-AS Routing in the Internet: RIP Intra-AS Routing in the Internet: OSPF Inter-AS Routing: BGP Broadcast and Multicast Routing Broadcast Routing Algorithms Multicast Summary 420 Homework Problems and Questions 421 Problems 424 Discussion Questions 435 Programming Assignment 436 Wireshark Labs 437 Interview: Vinton G. Cerf 438 Chapter 5 The Link Layer and Local Area Networks Link Layer: Introduction and Services The Services Provided by the Link Layer Where Is the Link Layer Implemented? 446

6 Table of Contents xxi 5.2 Error-Detection and -Correction Techniques Parity Checks Checksumming Methods Cyclic Redundancy Check (CRC) Multiple Access Protocols Channel Partitioning Protocols Random Access Protocols Taking-Turns Protocols" Local Area Networks (LANs) Link-Layer Addressing MAC Addresses Address Resolution Protocol (ARP) Ethernet Ethernet Frame Structure CSMA/CD: Ethernet's Multiple Access Protocol Ethernet Technologies Link-Layer Switches Forwarding and Filtering Self-Learning Properties of Link-Layer Switching Switches Versus Routers Virtual Local Area Networks (VLANs) PPP: The Point-to-Point Protocol PPP Data Framing Link Virtualization: A Network as a Link Layer A Day in the Life of a Web Page Request Summary 510 Homework Problems and Questions 511 Problems 513 Discussion Questions 520 Wireshark Labs 520 Interview: Simon S. Lam 521 Chapter 6 Wireless and Mobile Networks Introduction Wireless Links and Network Characteristics CDMA WiFi: Wireless LANs The Architecture The MAC Protocol The IEEE Frame 547

7 xxii Table of Contents Mobility in the Same IP Subnet Advanced Features in Beyond : Bluetooth and WiMAX Cellular Internet Access An Overview of Cellular Architecture Mobility Management: Principles Addressing Routing to a Mobile Node Mobile IP Managing Mobility in Cellular Networks Routing Calls to a Mobile User Handoffs in GSM Wireless and Mobility: Impact on Higher-layer Protocols Summary 587 Homework Problems and Questions 588 Problems 589 Discussion Questions 593 Wireshark Labs 593 Interview: Charlie Perkins 594 Chapter 7 Multimedia Networking Multimedia Networking Applications Examples of Multimedia Applications Hurdles for Multimedia in Today's Internet How Should the Internet Evolve to Support Multimedia Better? Audio and Video Compression Streaming Stored Audio and Video Accessing Audio and Video Through a Web Server Sending Multimedia from a Streaming Server to a Helper Application Real-Time Streaming Protocol (RTSP) Making the Best of the Best-Effort Service The Limitations of a Best-Effort Service Removing Jitter at the Receiver for Audio Recovering from Packet Loss Distributing Multimedia in Today's Internet: Content Distribution Networks Dimensioning Best-Effort Networks to Provide Quality of Service Protocols for Real-Time Interactive Applications RTP RTP Control Protocol (RTCP) 636

8 Table of Contents xxiii SIP H Providing Multiple Classes of Service Motivating Scenarios Scheduling and Policing Mechanisms Diffserv Providing Quality of Service Guarantees A Motivating Example Resource Reservation, Call Admission, Call Setup Guaranteed QoS in the Internet: Intserv and RSVP Summary 672 Homework Problems and Questions 673 Problems 674 Discussion Questions 681 Programming Assignment 682 Interview: Henning Schulzrinne 684 Chapter 8 Security in Computer Networks What Is Network Security? Principles of Cryptography Symmetric Key Cryptography Public Key Encryption Message Integrity and End-Point Authentication Cryptographic Hash Functions Message Authentication Code Digital Signatures End-Point Authentication Securing Secure PGP Securing TCP Connections: SSL The Big Picture A More Complete Picture Network-Layer Security: IPsec and Virtual Private Networks IPsec and Virtual Private Networks (VPNs) The AH and ESP Protocols Security Associations The IPset Datagram IKE: Key Management in IPsec Securing Wireless LANs Wired Equivalent Privacy (WEP) ЕЕЕ802.Ш 744

9 xxiv Table of Contents 8.8 Operational Security: Firewalls and Intrusion Detection Systems Firewalls Intrusion Detection Systems Summary 758 Homework Problems and Questions 760 Problems 762 Discussion Questions 768 Wireshark Lab 768 IPsec Lab 768 Interview: Steven M. Bellovin 769 Chapter 9 Network Management What Is Network Management? The Infrastructure for Network Management The Internet-Standard Management Framework Structure of Management Information: SMI Management Information Base: MIB SNMP Protocol Operations and Transport Mappings Security and Administration ASN.l Conclusion 799 Homework Problems and Questions 800 Problems 801 Discussion Questions 802 Interview: Jeff Case 803 References Index