1 The Internet, email, ebusiness and the worldwide web (WWW)
When, why and how did data networking and interworking start ? How did the Internet evolve ? Where will it lead ? And what does all that frightful jargon mean ? (the acronyms and the protocols). This chapter talks about the emergence of computer networking, the worldwide web (www), about ISPs (Internet service providers) and about where the Internet started - in the US Defense Department during the 1970s. It discusses the significance of the Internet Protocol (IP) today, and where it will lead. And most important of all - it starts 'unravelling' the jargon.

Keywords

• ARPANET
• bits
• bytes
• DCE (data circuit-terminating equipment)
• DECNET
• DTE (data terminal equipment)
• ebusiness
• EDI (electronic data interchange)
• electronic mail (email)
• Internet
• IP (Internet protocol)
• ISP (Internet service provider)
• LAN (local area network)
• NNI (network-network interface)
• OSI (open systems interconnection)
• SNA (systems network architecture)
• UNI (user-network interface)
• UNIX
• Worldwide web (www)
• X.25 (ITU-T recommendation for packet-switching)
 
2 Fundamentals of Data Communication and Packet Switching
'Data', a plural noun, is the term used to describe information which is stored in and processed by computers. This chapter explains how such data (computer text or graphics) is represented electronically and explains the basic physical principles and practicalities of telecommunications line transmission. We explain binary code, ASCII, EBCDIC, pixels and graphics arrays, computer-to-network interfaces, digital transmission, modems, synchronisation, the basics of packet-switching and the measures necessary to avoid data communications errors.

Keywords

• ASCII (American standard code for interchange of information)
• asynchonrous transmission
• binary code
• bit errors and their sources
• bit synchronization
• character synchronization
• CRC (cyclic redundancy check) code
• digital transmission
• duplex, half duplex and simplex transmission
• EBCDIC (extended binary code decimal interexchange code)
• error correction and error detection
• hexadecimal code 0x FFFFFF
• line codes
• modems and constellation patterns
• modulation - AM, FM, PM, FSK, PSK, QAM
• packet switching
• receivers and detection
• regeneration
• serial and parallel communication
• signal flow diagram
• statistical multiplexing
• synchronisation
• synchronous transmission
• VGA (video graphics array)
• virtual circuits
 
3 Basic Data Networks & Protocols

This chapter presents the basic components of a data network, and explains in detail the 'networking' or lower-layer protocols (protocol layers 1-3) which make them work. It explains physical and electrical interfaces and connectors, as well as physical, datalink, network, transport and higher-layer protocols: everything that goes to ensure efficient propagation across a network.


Keywords

• connectionless networking
• connection-oriented networking
• connectors, electrical interface and cables
• CSU (channel service unit)
• data block
• data flow control
• data frame
• DSU (digital service unit)
• DTE/DCE interface
• FCS (frame check sequence)
• flow control
• HDLC (higher-level datalink control)
• ISDN (integrated services digital network)
• label switching
• layer 1 - Physical layer
• layer 2 - datalink layer
• layer 2 addressing
• layer 2 frame format
• layer 3 - network layer
• layer 4 - transport layer
• layer 5 - session layer
• layer 6 - presentation layer
• layer 7 - application layer
• leaselines
• logical channels
• management, control and user planes
• multiplexing
• network synchronization
• PCI (protocol control information)
• PDH (plesiochronous digital hierachy)
• protocol encapsulation
• protocol layers and their functions
• protocol stack
• SAP (service access point)
• SDH (synchronous digital hierachy)
• SONET (synchronous optical network)
• synchronization
• tag-switching
• X.25 packet switching
 
4 Local Area Networks (LANs)
LANs are the most important means of conveying data between different computers and computer peripheral devices (printer, file server, electronic mail server, fax gateway, host gateway, computer printer, scanner etc.) within a single office, office building, or small campus. This chapter explains the various types of LAN and how they work. In particular, it is concerned with the ethernet LAN in its various forms - 10baseT, 100baseT (fast ethernet) and Gigabit ethernet - for ethernet has become the predominant standard for PC and server-based networking.

Keywords

• block code
• canonical transmission format (least significant bit first)
• collapsed backbone LAN
• CSMA/CD (carrier sense multiple access with collision detection)
• ethernet LAN
• fast ethernet
• FDDI (fibre distributed data interface)
• gateway
• Gigabit ethernet
• IEEE 802 standards
• IEEE 802.2 (LLC)
• IEEE 802.3 (ethernet)
• IEEE 802.11 (WLAN)
• LAN backbone
• LAN bridge
• LAN hub
• LAN (local area network)
• LAN repeater
• LAN segment
• LAN switch
• LLC (logical link control)
• MAC (medium access control)
• MAN (metropolitan area network)
• multilevel transmission (MLT)
• PHY (physical layer protocol)
• PMD (physical medium dependent)
• SAT (source address table)
• segmentation and reassembly (SAR)
• SMDS/DQDB (switched multimegabit data service / dual queue dual bus)
• source route bridging (SRB)
• STP (spanning tree protocol)
• token bus
• token ring LAN
• VLAN (virtual-bridged LAN)
• WLAN (wireless LAN)
 
5 WANs, routers and the Internet Protocol (IP)
This chapter describes how wide area networks (WANs) for data communication can be built using routers and the Internet Protocol. It explains how the routers work and the aspects of the Internet Protocol (including the IP-addressing scheme) which make router functions possible. We shall discuss in detail the two most important variations of the Internet protocol - version 4 (IPv4) and version 6 (IPv6) - and we shall cover the functions of an IP-based router, as well as the various types of network communication made possible by IP - unicasting, broadcasting, multicasting and anycasting.

Keywords

• anycasting
• broadcasting
• checksum
• CIDR (classless inter-domain routing)
• classful addressing
• datagram
• DiffServ (differentiated services)
• dynamic routing
• forwarding
• fragmentation
• gateway
• ICMP (Internet control message protocol)
• ICMPv4 (Internet control message protocol version 4)
• ICMPv6 (Internet control message protocol version 6)
• IGMP (Internet group management protocol)
• Internet address
• IP (Internet protocol)
• IPv4 (Internet protocol version 4)
• IPv4 addressing
• IPv6 (Internet protocol version 6)
• IPv6 addressing
• logical address
• multicasting
• NAT (network address translation)
• non-canonical transmission format (most significant bit first)
• physical address
• router
• static routing
• TOS (type-of-service)
• unicasting
• VLSM (variable length subnet mask)
• WAN (wide area network)
 
6 Routing Tables and Protocols
Routing protocols, metrics, routing algorithms, the calculation of routing distance (or cost) and routing policies are the focus of this chapter. It discusses all the common routing protocols and goes on to set-out in detail the function and use of the most popular ones: RIP (routing information protocol), OSPF (open shortest path first) and BGP4 (border gateway protocol 4). It also covers the related topics of address resolution, IP-address assignment and IP-parameter configuration of hosts, since these are also an important means by which routers collecting the information necessary to complete the routing table.

Keywords

• address resolution
• advertisement
• ageing
• ARP (address resolution protocol)
• autonomous system (AS)
• BGP (border gateway protocol)
• BOOTP (bootstrap protocol)
• border node
• circular routing
• DHCP (dynamic host configuration protocol)
• distance vector protocol (DVP)
• EGP (exterior gateway protocol)
• EIGRP (enhanced interior gateway routing protocol)
• flooding
• hello protocol
• IGP (interior gateway protocol)
• IGRP (interior gateway routing protocol)
• inARP (inverse address resolution protocol)
• IP address assignment
• IS/IS (intermediate system-intermediate system)
• link state protocol (LSP)
• neighbour discovery
• OSPF (open shortest path first)
• path cost
• path distance
• RARP (reverse address resolution protocol)
• RIP (routing information protocol)
• route dampening
• route flapping
• route redistribution
• routing algorithms and metrics
• routing cost
• routing distance
• routing management
• routing tables
• stability of routing
 
7 Transport Services and Protocols
This chapter considers the three main types of transport services: connectionless transport service (CLTS); connection-oriented transport service (COTS) and a special form of connection-oriented service called flow- or stream-oriented transport service. It describes in detail the IP-suite protocols which provide for these services: UDP (user datagram protocol - provides for connectionless service); TCP (transmission control protocol - provides for connection-oriented service), MPLS (multiprotocol label switching - provides for flow-based communication) and RSVP (resource reservation protocol - provides for bandwidth reservation, as particularly needed in associated with flow-based communication). The related real-time application transport protocol (RTP) appears in chapter 10.

Keywords

• acknowledgement (ACK)
• bandwidth reservation
• connectionless transport service (CLTS)
• congestion control
• connection-oriented transport service (COTS)
• flow control
• label-switching
• MPLS (multiprotocol label switching)
• port number
• RSVP (resource reservation protocol)
• segment
• sequence number
• socket
• tag switching
• TCP (transmission control protocol)
• TCP flow control
• UDP (user datagram -switching
 
8 P-Networks in practice: Components, Backbone and Access
This chapter is concerned with building real IP-networks; with the structure and components of such networks. It starts by considering the architecture of a typical IP-based data network and discusses in detail the different types of routers, the WAN technologies available for interconnecting them and the considerations which should go into backbone network topology design. It covers the access network, the technologies available to connect end-users to the network and the relative strengths of each: leaselines, dial-in, xDSL and wireless. It also introduces two important protocols used in the access arena: PPP (point-to-point protocol) and PPPoE (point-to-point protocol over Ethernet). These protocols are important for discovering and configuring access network connections.

Keywords

• access network technologies
• access router
• ATM (asynchronous transfer mode)
• cable modems
• core router
• dial-in access
• dial-on-demand
• DWDM (dense wave division multiplexing)
• EFM (ethernet in the first mile)
• enterprise network
• extranet
• fibre types
• frame relay
• gateway
• IEEE 802.11
• Internet
• Internet exchanges (IX, INX, MAEs)
• intranet
• IP backbone network technologies
• ISP (Internet service provider)
• leaseline
• NAS (network access server)
• network interconnection
• peering
• POSIP (packet over SONET/SDH)
• PPP (point-to-point protocol)
• PPPoE (PPP over ethernet)
• satellite transmission
• SDH (synchronous digital hierarchy)
• SONET (synchronous optical network)
• TAPI (telephone application programming interface)
• VPN (virtual private network)
• WAP (wireless application protocol)
• WDM (wave division multiplexing)
• wireless technology
• xDSL
 
9 Managing the Network
This chapter reviews the current state-of-the-art means available for IP-network management. It explains how the simple network management protocol (SNMP) was conceived to monitor and control individual items of network equipment. It also explains management information bases (MIBs) and Remote MONitoring (RMON).

Keywords

• ASN.1 (abstract syntax notation 1)
• CMIP (common management information protocol)
• console port
• FCAPS (fault, configuration, accounting, performance and security management)
• Internet mib-2 (MIB-II)
• ISO management model
• localising faults
• loopback
• managed objects
• MIB (management information base)
• network element manager (NEM)
• network management system (NMS)
• PING (packet Internet groper)
• polling
• probe
• Q3-interface
• RMON (remote network monitoring)
• SMI (structure of management information)
• SNMP (simple network management protocol)
• SNMPv1, SNMPv2 and SNMPv3
• SNMP proxy agent
• SNMP trap
• statistics
• structure of management information (SMIv1 and SMIv2)
• TMN (telecommunications management network)
• troubleshooting
 
10 Data Networking and Internet Applications
This chapter introduces the most important application layer protocols used with IP (Internet protocol)-networks and explains how these provide the main foundation of modern 'networked computing'. In particular, it explains in detail: Telnet, FTP (file transfer protocol), TFTP (trivial file transfer protocol), SSH (secure shell) and RTP (real-time application transport protocol). It introduces the DNS (domain name system) and SMTP (simple mail transfer protocol) protocols though the detailed protocol functions and formats of DNS and SMTP are covered by chapters 11 and 12 respectively.

Keywords

• application layer protocols
• ASN.1 (abstract syntax notation 1)
• computer applications & data networks
• FTP (file transfer protocol)
• NVT (network virtual terminal)
• NVT-ASCII character set
• object-oriented protocol
• RTP (real-time application transport protocol)
• SSH (secure shell)
• Telnet
• TFTP (trivial file transfer protocol)
• UNIX protocols
• VOIP (voice-over-IP)
 
11 The Worldwide Web (WWW)
The four technologies which emerged by 1990 to create the worldwide web are: the domain name system (DNS), the hypertext transfer protocol (http), the hypertext markup language (html) and the web browser. This chapter describes in detail each of the four technologies in turn. It also explains and illustrates how the use of web technology has revolutionised the design of modern 'distributed computing' applications.

Keywords

• cache
• DNS (domain name system)
• DNS protocol
• HTTP (hypertext transfer protocol)
• HTTP gateway
• HTTP proxy
• HTML (hypertext markup language)
• ICP (Internet cache protocol)
• name server
• resource record (RR)
• tunnel
• URI (universal resource indicator)
• URL (universal resource locator)
• URN (universal resource name)
• web-based applications
• web browser
• WINS (Windows Internet name service)
• www (worldwide web)
 
12 Electronic Mail
This chapter we explain the principles of electronic mail - in particular: Internet mail. We discuss the format of messages and mail addresses; the message transfer system (MTS) and the various protocols associated with them: SMTP (simple mail transfer protocol), IMAP (Internet message access protocol) and POP (post office protocol).

Keywords

• email (electronic mail)
• email address
• envelope, content-header and content-body
• IMAP (Internet mail access protocol)
• Internet mail system
• Internet message format (RFC 2822)
• mailbox
• media types
• MHS (message handling system)
• MIME (multipurpose Internet mail extension)
• MTA (message transfer agent)
• MTS (mail transfer system)
• POP (post office protocol)
• SMTP (simple mail transfer protocol)
 
13 Data Network Security
This chapter describes the various levels of information protection provided by different data network security means, explaining how they work and the threats (both malicious and non-malicious) which they attempt to eliminate. It discusses simple password techniques, methods of path protection, tunneling, firewalls, VPNs (virtual private networks), as well as digital signatures and data encryption. The underlying philosophy is that in developing a full security strategy for data networking, it is important to understand the risks, consider the motivations of 'hackers' and develop a pragmatic policy to counter the most likely and most threatening dangers.

• AAA (authentication, authorization and accounting)
• ACL (access control list)
• callback
• CHAP (challenge handshake authentication protocol)
• CLI (calling line identity)
• content filters and virus scanners
• denial of service (DOS) attacks
• DES (Defense encrpytion standard)
• digital certificate
• digital signature
• DMZ (demilitarized zone)
• EMI (electromagnetic interference)
• encapsulation
• encryption - symmetric and asymmetric
• extranet
• firewall
• firewall holes
• firewall intrustion & detection
• GRE (generic routing encapsulation)
• intranet
• intrusion and intrusion detection
• IPsec (Internet protocol security architecture)
• L2TP (layer 2 tunneling protocol)
• message digests : MD2, MD4, MD5, SHA-1
• mobile IP (IP mobility)
• NAS (network access server)
• NAT (network address translation)
• PAP (password authentication protocol)
• password
• PKC (public key cryptography)
• PKI (public key infrastructure)
• PPTP (point-to-point tunneling protocol)
• proxy server
• RADIUS (remote authentication dial-in user service)
• SOCKS
• spoofing
• stateful inspection
• TACACS/TACACS+ (terminal access controller - access control system)
• tunneling
• VPN (virtual private network)
 
14 Quality of Service (QOS), Network Performance and Optimisation
This chapter sets out an objective framework for measuring telecommunications network quality of service (QOS). It aims to provide a practical framework for the continuous monitoring of network quality, describing the symptoms of typical network problems to look out for, the methods available to diagnose problems and the tools available to overcome them. It sets out a structured process for network design and administration with the goal of optimum network quality and efficiency: avoiding problems as far as possible before they arise.

Keywords

• admission control
• back-up
• configuring applications
• congestion control
• COS (class of service)
• forecasting
• interconnection
• latency
• load balancing
• network analysis - top talkers, average transaction delay, usage, link utilization etc
• network availability
• network reliability
• network dimensioning
• network management
• network management system (NMS)
• network performance (NP)
• network restoration
• network topology
• network traffic theory
• packet shaping
• peering
• QOS (quality of service)
• redundant networks
• router redundancy
• reverse multiplexing
• TOS (type of service)
• traffic engineering
• VRRP (virtual router redundancy protocol)
 
15 Challenges ahead for IP (short chapter only)
This short final chapter assesses the five greatest challenges to be overcome as the Internet protocol (IP) continues to be developed to meet changing present and future needs.

Keywords

• accounting
• financing
• interconnection
• network scaling
• peering