Technology - Internet - Volume 1 - Infrastructure

This report is a technical introduction, for people without an engineering background, to the Internet’s infrastructure and to its major protocols and applications.

We begin with an overview of the Internet’s future, including two challenges to its continuing stability – the crisis in routing and addressing and the proliferation of ‘botnets’: criminally controlled networks of hundreds of thousands of home and office computers which are used for spam, fraud and denial of service attacks.

The crisis in routing and addressing involves the imminent depletion of fresh IPv4 address space around 2012 and difficulties with the core Internet routers and the border routers of the networks of ISPs and major organisational users. The global routing system is not expected to cope well with the continual increase in the current 200,000 separately routed divisions of the IPv4 address space. IPv6 routing will be even more problematic if and when its adoption becomes ubiquitous. The current approaches to addressing and routing are failing to keep up with the needs of the growing number of interconnected networks, including especially those which require multihoming: two or more connections to upstream ISPs.

We describe the basics of Transmission Control Protocol/Internet Protocol (TCP/IP), User Datagram Protocol (UDP) and TCP packets, which are the basis of all Internet communications. We also discuss how IPv6, the next generation of Internet addressing, may be adopted. IPv6’s widespread adoption for servers and desktop computers is far from assured, with concern about routing problems and with the difficulties inherent in two-stack adoption. However IPv6 is likely to be widely used in China, for some new cellular mobile networks and for proposed new generations of IP-equipped appliances and devices.

Using a web-browsing example, we describe client-server communications, with HyperText Transport Protocol (HTTP) operating over a two-way TCP session. We describe basic routing, the Domain Name System (DNS) and the Simple Mail Transport Protocol (SMTP, Post Office Protocol (POP) and Internet Message Access Protocol (IMAP) protocols which are the basis of the email system. We also describe File Transfer Protocol (FTP) and the encrypted protocols: Secure Shell (SSH), SSH tunnelling, Secure Copy (SCP) and Secure FTP (SFTP). We discuss Internet Relay Chat (IRC) and more modern, proprietary instant-messaging protocols and the local area filesystem networks Network File System (NFS), NetBIOS and SAMBA – the open-source implementation of Microsoft Windows printing and file services.

We discuss the Peer to Peer (P2P) file sharing networks, which now comprise a major portion of Internet traffic. Bittorrent and other P2P systems send continual, scattered patterns of packets with high upstream volumes from home and office computers, placing strain on DSL and particularly HFC cable modem access networks. We also review anonymity networks, including TOR (The Onion Router). These provide potentially crucial communications for people in oppressive countries, but are also a haven for hackers and other criminals.

The BuddeComm Technical Library is intended for readers with minimal technical background, and for technical specialists in related fields. The Library’s Biennial and Web Reports provide an overview of a field together with sufficient low level detail to enable readers to develop a genuine understanding of the various technologies. While most of the material is introductory and of a tutorial nature, we also provide critical viewpoints of particular technologies and discuss how different technologies compete with each other or can be used together. This is intended to enable our customers to critically evaluate proposals and to extend their ability to plan their own projects and investments.

The companion volume to this report is available and includes information on Web Development and Audio-Visual Coding technologies: 2007 Internet Technology - Volume 2 - Web Development & Audio-Visual Coding