Computer Networks: An Open Source Approach

Tittle
Contents
1 Fundamentals
	1.1 Requirements for Computer Networking
		1.1.1 Connectivity: Node, Link, Path
		Historical Evolution: Link Standards
		Historical Evolution: ATM Faded
		1.1.2 Scalability: Number of Nodes
		1.1.3 Resource Sharing
		Principle in Action: Datacom vs. Telecom
	1.2 Underlying Principles
		1.2.1 Performance Measures
		Principle in Action: Little’s Result
		1.2.2 Operations at Control Plane
		1.2.
		Operations at Data Plane
		1.2.4 Interoperability
	1.3 The Internet Architecture
		1.3.1 Solutions to Connectivity
		Principle in Action: Constantly Challenged Statelessness
		1.3.2 Solutions to Scalability
		1.3.3 Solutions to Resource Sharing
		1.3.4 Control-Plane and Data-Plane Operations
		Principle in Action: Flavors of the Internet Architecture
	1.4 Open Source Implementations
		1.4.1 Open vs. Closed
		1.4.2 Software Architecture in Linux Systems
		1.4.3 Linux Kernel
		1.4.4 Clients and Daemon Servers
		1.4.5 Interface Drivers
		1.4.6 Device Controllers
	1.5 Book Roadmap: A Packet’s Life
		1.5.1 Packet Data Structure: sk_buff
		1.5.2 A Packet’s Life in a Web Server
		1.5.3 A Packet’s Life in a Gateway
		Performance Matters: From Socket to Driver within a Server
		Performance Matters: From Input Port to Output Port within a Router
		Principle in Action: A Packet’s Life in the Internet
	1.6 Summary
		Common Pitfalls
		Further Readings
		Frequently Asked Questions
		Exercises
2 Physical Layer
	2.1 General Issues
		2.1.1 Data and Signal: Analog or Digital
		Principle in Action: Nyquist Theorem vs. Shannon Theorem
		2.1.2 Transmission and Reception Flows
		2.1.3 Transmission: Line Coding and Digital Modulation
		2.1.4 Transmission Impairments
		Historical Evolution: Software Defi ned Radio
	2.2 Medium
		2.2.1 Wired Medium
		2.2.2 Wireless Medium
	2.3 Information Coding and Baseband Transmission
		2.3.1 Source and Channel Coding
		2.3.2 Line Coding
		Open Source Implementation 2.1: 8B/10B Encoder
	2.4 Digital Modulation and Multiplexing
		2.4.1 Passband Modulation
		2.4.2 Multiplexing
	2.5 Advanced Topics
		2.5.1 Spread Spectrum
		2.5.2 Single-Carrier vs. Multiple-Carrier
		2.5.3 Multiple Inputs, Multiple Outputs (MIMO)
		Open Source Implementation 2.2: IEEE 802.11a Transmitter with OFDM
		Historical Evolution: Cellular Standards
		Historical Evolution: LTE-Advanced vs. IEEE 802.16m
	2.6 Summary
		Common Pitfalls
		Further Readings
		Frequently Asked Questions
		Exercises
3 Link Layer
	3.1 General Issues
		3.1.1 Framing
		3.1.2 Addressing
		3.1.3 Error Control and Reliability
		Principle in Action: CRC or Checksum?
		Principle in Action: Error Correction Code
		Open Source Implementation 3.1: Checksum
		Open Source Implementation 3.2: Hardware CRC-32
		3.1.4 Flow Control
		3.1.5 Medium Access Control
		3.1.6 Bridging
		3.1.7 Link-Layer Packet Flows
		Open Source Implementation 3.3: Link-Layer Packet Flows in Call Graphs
	3.2 Point-to-Point Protocol
		3.2.1 High-Level Data Link Control (HDLC)
	3.3 Ethernet (IEEE 802.3)
		3.3.1 Ethernet Evolution: A Big Picture
		Historical Evolution: Competitors to Ethernet
		3.3.2 The Ethernet MAC
		Open Source Implementation 3.5: CSMA/CD
		Historical Evolution: Power-Line Networking: HomePlug
		3.3.3 Selected Topics in Ethernet
		Historical Evolution: Backbone Networking: SONET/SDH and MPLS
		Historical Evolution: First-Mile Networking: xDSL and Cable Modem
	3.4 Wireless Links
		3.4.1 IEEE 802.11 Wireless LAN
		Principle in Action: Why Not CSMA/CD in WLAN?
		Open Source Implementation 3.6: IEEE 802.
		MAC Simulation with NS-2
		3.4.2 Bluetooth Technology
		3.4.3 WiMAX Technology
		Historical Evolution: Comparing Bluetooth and IEEE 802.11
		Historical Evolution: Comparing 3G, LTE, and WiMAX
	3.5 Bridging
		3.5.1 Self-Learning
		Historical Evolution: Cut-Through vs. Store-and- Forward
		Open Source Implementation 3.7: Self- Learning Bridging
		3.5.2 Spanning Tree Protocol
		Open Source Implementation 3.8: Spanning Tree
		3.5.3 Virtual LAN
		Principle in Action: VLAN vs. Subnet
	3.6 Device Drivers of a Network Interface
		3.6.1 Concepts of Device Drivers
			3.6.2 Communicating with Hardware in a Linux Device Driver
			Open Source Implementation 3.9: Probing I/O Ports, Interrupt Handling, and DMA
			Open Source Implementation 3.10: The Network Device Driver in Linux
			Performance Matters: Interrupt and DMA Handling within a Driver
			Historical Evolution: Standard Interfaces for Drivers
		3.7 Summary
			Common Pitfalls
			Further Readings
			Frequently Asked Questions
			Exercises
	3.2.2 Point-to-Point Protocol (PPP)
	3.2.3 Internet Protocol Control Protocol (IPCP)
	Open Source Implementation 3.4: PPP Drivers
	3.2.4 PPP over Ethernet (PPPoE)
4 Internet Protocol Layer
	4.1 General Issues
		4.1.1 Connectivity Issues
		4.1.2 Scalability Issues
		Principle in Action: Bridging vs. Routing
		4.1.3 Resource Sharing Issues
		4.1.4 Overview of IP-Layer Protocols and Packet Flows
		Open Source Implementation 4.1: IP-Layer Packet Flows in Call Graphs
		Performance Matters: Latency within the IP Layer
	4.2 Data-Plane Protocols: Internet Protocol
		4.2.1 Internet Protocol Version 4
		Open Source Implementation 4.2: IPv4 Packet Forwarding
		Performance Matters: Lookup Time at Routing Cache and Table
		Open Source Implementation 4.3: IPv
		Checksum in Assembly
		Open Source Implementation 4.4: IPv
		Fragmentation
		4.2.2 Network Address Translation (NAT)
		Principle in Action: Different Types of NAT
	Principle in Action: Messy ALG in NAT
	Open Source Implementation 4.5: NAT
	Performance Matters: CPU Time of NAT Execution and Others
	4.3 Internet Protocol Version 6
		Historical Evolution: NAT vs. IPv6
		4.3.1 IPv6 Header Format
		4.3.2 IPv6 Extension Header
		4.3.3 Fragmentation in IPv6
		4.3.4 IPv6 Address Notation
		4.3.5 IPv6 Address Space Assignment
		4.3.6 Autoconfi guration
		4.3.7 Transition from IPv4 to IPv6
	4.4 Control-Plane Protocols: Address Management
		4.4.1 Address Resolution Protocol
		Open Source Implementation 4.6: ARP
		4.4.2 Dynamic Host Confi guration
		Open Source Implementation 4.7: DHCP
	4.5 Control Plane Protocols: Error Reporting
		4.5.1 ICMP Protocol
		Open Source Implementation 4.8: ICMP
	4.6 Control Plane Protocols: Routing
		4.6.1 Routing Principles
		Principle in Action: Optimal Routing
		4.6.2 Intra-Domain Routing
		Open Source Implementation 4.9: RIP
		4.6.3 Inter-Domain Routing
		Open Source Implementation 4.10: OSPF
		Performance Matters: Computation Overhead of Routing Daemons
		Open Source Implementation 4.11: BGP
	4.7 Multicast Routing
		4.7.1 Shifting Complexity to Routers
		4.7.2 Group Membership Management
		4.7.3 Multicast Routing Protocols
		Principle in Action: When the Steiner Tree Differs from the Least-Cost-Path Tree
			4.7.4 Inter-Domain Multicast
			Principle in Action: IP Multicast or Application Multicast?
			Open Source Implementation 4.12: Mrouted
		4.8 Summary
			Common Pitfalls
			Further Readings
			Frequently Asked Questions
			Exercises
5 Transport Layer
	5.1 General Issues
		5.1.1 Node-to-Node vs. End-to-End
		5.1.2 Error Control and Reliability
		5.1.3 Rate Control: Flow Control and Congestion Control
		5.1.4 Standard Programming Interfaces
		5.1.5 Transport-Layer Packet Flows
		Open Source Implementation 5.1: Transport- Layer Packet Flows in Call Graphs
	5.2 Unreliable Connectionless Transfer: UDP
		5.2.1 Header Format
		5.2.2 Error Control: Per-Segment Checksum
		Open Source Implementation 5.2: UDP and TCP Checksum
		5.2.3 Carrying Unicast/Multicast Real-Time Traffi c
	5.3 Reliable Connection-Oriented Transfer: TCP
		5.3.1 Connection Management
		5.3.2 Reliability of Data Transfers
		5.3.3 TCP Flow Control
		Open Source Implementation 5.3: TCP Sliding- Window Flow Control
		5.3.4 TCP Congestion Control
		Historical Evolution: Statistics of TCP Versions
		Open Source Implementation 5.4: TCP Slow Start and Congestion Avoidance
		Principle in Action: TCP Congestion Control Behaviors
	5.4 Socket Programming Interfaces
		5.4.1 Socket
		5.4.2 Binding Applications through UDP and TCP
		Principle in Action: SYN Flooding and Cookies
		Open Source Implementation 5.7: Socket Read/ Write Inside Out
		Performance Matters: Interrupt and Memory Copy at Socket
		5.4.3 Bypassing UDP and TCP
		Open Source Implementation 5.8: Bypassing the Transport Layer
		Open Source Implementation 5.9: Making Myself Promiscuous
		Open Source Implementation 5.10: Linux Socket Filter
	5.5 Transport Protocols for Real-Time Traffi c
		5.5.1 Real-Time Requirements
		Principle in Action: Streaming: TCP or UDP?
		5.5.2 Standard Data-Plane Protocol: RTP
		5.5.3 Standard Control-Plane Protocol: RTCP
		Historical Evolution: RTP Implementation Resources
	5.6 Summary
		Common Pitfalls
		Further Readings
		Frequently Asked Questions
		Exercises
	5.3.5 TCP Header Format
	5.3.6 TCP Timer Management
	Open Source Implementation 5.5: TCP Retransmission Timer
	Open Source Implementation 5.6: TCP Persist Timer and Keepalive Timer
	5.3.7 TCP Performance Problems and Enhancements
	Historical Evolution: Multiple-Packet-Loss Recovery in NewReno, SACK, FACK, and Vegas
	Principle in Action: TCP for the Networks with Large Bandwidth-Delay Product
6 Application Layer
	Historical Evolution: Mobile Applications
	6.1 General Issues
		6.1.1 How Ports Work
		6.1.2 How Servers Start
		6.1.3 Classifi cation of Servers
		Historical Evolution: Cloud Computing
		6.1.4 Characteristics of Application Layer Protocols
	6.2 Domain Name System (DNS)
		6.2.1 Introduction
		6.2.2 Domain Name Space
		6.2.3 Resource Records
		6.2.4 Name Resolution
		Historical Evolution: Root DNS Servers Worldwide
		Open Source Implementation 6.1: BIND
	6.3 Electronic Mail (E-Mail)
		6.3.1 Introduction
		6.3.2 Internet Message Standards
		6.3.3 Internet Mail Protocols
		Historical Evolution: Web-Based Mail vs. Desktop Mail
		Open Source Implementation 6.2: qmail
	6.4 World Wide Web (WWW)
		6.4.1 Introduction
		6.4.2 Web Naming and Addressing
		6.4.3 HTML and XML
		6.4.4 HTTP
		Principle in Action: Non-WWW Traffi c Over Port 80 or HTTP
		Historical Evolution: Google Applications
		6.4.5 Web Caching and Proxying
		Open Source Implementation 6.3: Apache
		Performance Matters: Throughput and Latency of a Web Server
	6.5 File Transfer Protocol (FTP)
		6.5.
		Introduction
		6.5.2 The Two-Connection Operation Model: Out-of-Band Signaling
		Historical Evolution: Why Out-of-Band Signaling in FTP?
		6.5.3 FTP Protocol Messages
		Open Source Implementation 6.4: wu-ftpd
	6.6 Simple Network Management Protocol (SNMP)
		6.6.1 Introduction
		6.6.2 Architectural Framework
		6.6.3 Management Information Base (MIB)
		6.6.4 Basic Operations in SNMP
		Open Source Implementation 6.5: Net-SNMP
	6.7 Voice over IP (VoIP)
		6.7.1 Introduction
		Historical Evolution: Proprietary VoIP Services—Skype and MSN
		6.7.2 H.323
		6.7.3 Session Initialization Protocol (SIP)
		Historical Evolution: H.323 vs. SIP
		Open Source Implementation 6.6: Asterisk
	6.8 Streaming
		6.8.1 Introduction
		6.8.2 Compression Algorithms
		6.8.3 Streaming Protocols
		Historical Evolution: Streaming with Real Player, Media Player, QuickTime, and YouTube
		6.8.4 QoS and Synchronization Mechanisms
		Open Source Implementation 6.7: Darwin Streaming Server
	6.9 Peer-to-Peer Applications (P2P)
		6.9.1 Introduction
		Historical Evolution: Popular P2P Applications
		Historical Evolution: Web 2.0 Social Networking: Facebook, Plurk, and Twitter
		6.9.2 P2P Architectures
		6.9.3 Performance Issues of P2P Applications
		6.9.4 Case Study: BitTorrent
		Open Source Implementation 6.8: BitTorrent
	6.10 Summary
		Common Pitfalls
			Further Readings
			Frequently Asked Questions
			Exercises
7  Internet QoS
	Historical Evolution: The QoS Hype around 2000s
	7.1 General Issues
		7.1.1 Signaling Protocol
		7.1.2 QoS Routing
		7.1.3 Admission Control
		7.1.4 Packet Classifi cation
		7.1.5 Policing
		7.1.6 Scheduling
		Open Source Implementation 7.1: Traffi c Control Elements in Linux
	7.2 QoS Architectures
		7.2.1 Integrated Services (IntServ)
		7.2.2 Differentiated Services (DiffServ)
		Principle in Action: Why Both DiffServ and IntServ Failed
		Principle in Action: QoS in Wireless Links
	7.3 Algorithms for QoS Components
		7.3.1 Admission Control
		Open Source Implementation 7.2: Traffi c Estimator
		7.3.2 Flow Identifi cation
		Open Source Implementation 7.3: Flow Identifi cation
		7.3.3 Token Bucket
		Open Source Implementation 7.4: Token Bucket
		7.3.4 Packet Scheduling
		Open Source Implementation 7.5: Packet Scheduling
		7.3.5 Packet Discarding
		Open Source Implementation 7.6: Random Early Detection (RED)
		Principle in Action: QoS Components in Daily Usage Today
	7.4 Summary
		Common Pitfalls
		Further Readings
		Frequently Asked Questions
		Exercises
8 Network Security
	8.1 General Issues
		8.1.1 Data Security
		8.1.2 Access Security
		8.1.3 System Security
	8.2 Data Security
		8.2.1 Principles of Cryptography
		Open Source Implementation 8.1: Hardware 3DES
		Principle in Action: Secure Wireless Channels
		8.2.2 Digital Signature and Message Authentication
		Open Source Implementation 8.2: MD5
		8.2.3 Link Layer Tunneling
		8.2.4 IP Security (IPSec)
		Open Source Implementation 8.3: AH and ESP in IPSec
		8.2.5 Transport Layer Security
		Historical Evolution: HTTP Secure (HTTPS) and Secure Shell (SSH)
		8.2.6 Comparison on VPNs
	8.3 Access Security
		8.3.1 Introduction
		8.3.2 Network/Transport Layer Firewall
		Open Source Implementation 8.4: Netfi lter and iptables
		8.3.3 Application Layer Firewall
		Open Source Implementation 8.5: FireWall Toolkit (FWTK)
		Principle in Action: Wireless Access Control
	8.4 System Security
		8.4.1 Information Gathering
		8.4.2 Vulnerability Exploiting
		8.4.3 Malicious Code
		Open Source Implementation 8.6: ClamAV
		8.4.4 Typical Defenses
		Principle in Action: Bottleneck in IDS
		Principle in Action: Wireless Intrusions
		Open Source Implementation 8.7: Snort
		Open Source Implementation 8.8: SpamAssassin
		Performance Matters: Comparing Intrusion Detection, Antivirus, Anti-Spam, Content Filtering, and P2P Classifi cation
	8.5 Summary
		Common Pitfalls
		Further Readings
		Frequently Asked Questions
		Exercises
Appendices A Who’s Who
	A.1 IETF: Defi ning RFCs
		A.1.1 IETF History
		Historical Evolution: Who’s Who in IETF
		A.1.2 The RFC Process
		A.1.3 The RFC Statistics
	A.2 Open Source Communities
		A.2.1 Beginning and Rules of the Game
		A.2.2 Open Source Resources
		A.2.3 Websites for Open Source
		A.2.4 Events and People
	A.3 Research and Other Standards Communities
	A.4 History
		Further Readings
B Linux Kernel Overview
	B.1 Kernel Source Tree
	B.2 Source Code for Networking
	B.3 Tools for Source Code Tracing
		Example: Trace of Reassembly of IPv
		Fragments
		Further Readings
C Development Tools
	C.1 Programming
		C.1.1 Text Editor – vim and gedit
		C.1.2 Compiler – gcc
		C.1.3 Auto-Compile – make
	C.2 Debugging
		C.2.1 Debugger – gdb
		C.2.2 GUI Debugger – ddd
		C.2.3 Kernel Debugger – kgdb
	C.3 Maintaining
		C.3.1 Source Code Browser – cscope
		C.3.2 Version Control – Git
	C.4 Profi ling
		C.4.1 Profi ler – gprof
		C.4.2 Kernel Profi ler – kernprof
	C.5 Embedding
		C.5.1 Tiny Utilities – busybox
		C.5.2 Embedding Development – uClibc and buildroot
		Further Readings
D Network Utilities
	D.1 Name-Addressing
		D.1.1 Internet’s Who-Is-Who – host
		D.1.2 LAN’s Who-Is-Who – arp
		D.1.3 Who Am I – ifconfig
	D.2 Perimeter-Probing
		D.2.1 Ping for Living – ping
		D.2.2 Find the Way – tracepath
	D.3 Traffi c-Monitoring
		D.3.1 Dump Raw Data – tcpdump
		D.3.2 GUI Sniffer – Wireshark
		D.3.3 Collect Network Statistics – netstat
	D.4 Benchmarking
		D.4.1 Host-to-Host Throughput – ttcp
	D.5 Simulation and Emulation
		D.5.1 Simulate the Network – ns
		D.5.2 Emulate the Network – NIST Net
	D.6 Hacking
		D.6.1 Exploit Scanning – Nessus
		Further Readings
Index