Glossary

BSD, Berkeley System Distribution

A family of Unix versions developed by Bill Joy and others at the University of California at Berkeley, originally for the DEC VAX and PDP-11 computers, and subsequently ported to almost all modern general-purpose computers. BSD Unix incorporates paged virtual memory, TCP/IP networking enhancements and many other features [FOLDOC].

DNS, Domain Name System

This system is used to convert IP Addresses into hostnames. It is also used to determine where mail should be routed for a domain.

FTP, File Transfer Protocol

FTP used to be used to transfer large files over the internet. It is an archaic protocol.

HTML, Hypertext Markup Language

A system to mark up documents. It is the most common format used for documents on the world-wide web, and is the format that web browsers display.

HTTP, Hypertext Transfer Protocol

This protocol was originally used to transfer HTML documents between machines connected to the internet. It has become the standard protocol for transferring all types of documents over the world-wide web.

IMAP, Internet Message Access Protocol

The Internet Message Access Protocol (IMAP) is one of the two most prevalent Internet standard protocols for e-mail retrieval, the other being the Post Office Protocol (POP). Virtually all modern e-mail clients and mail servers support both protocols as a means of transferring e-mail messages from a server.

IP, Internet Protocol

The network layer for the TCP/IP protocol suite widely used on Ethernet networks, defined in STD 5, RFC 791. IP is a connectionless, best-effort packet switching protocol. It provides packet routing, fragmentation and re-assembly through the data link layer.

+ IPv4 is the version in widespread use and IPv6 was just beginning to come into use in 2000 but was still not widespread by 2008 [FOLDOC].

IP Address

IP addresses come in two flavours, reflecting the two versions of IP used.

+ An IPv4 address is a 32 bit number generally represented as a dotted quad e.g. 10.20.30.40. There is a limit of just under 4.3 billion IPv4 addresses, which is slowly being reached, which necessitated the invention of IPv6.

+ An IPv6 address is a 128 bit number, generally represented as a hexadecimal number, split into nibbles of up to four digits, separated by colons, e.g. 2001:41c8:12::34. There are up to 2128 or 3 × 1038 addresses available in IPv6.

ISP, Internet Service Provider

A company which provides other companies or individuals with access to, or presence on, the Internet. Most ISPs are also Internet Access Providers; extra services include help with design, creation and administration of World-Wide Web sites, training and administration of intranets and domain name registration [FOLDOC].

ManageSieve

ManageSieve is a protocol that is allows Sieve filters to be managed remotely, testing any filters before allowing them to be used.

MTA, Mail Transfer Agent

A mail transfer agent is a computer process or software agent that transfers electronic mail messages from one computer to another, in single hop application-level transactions. A MTA implements both the client (sending) and server (receiving) portions of the Simple Mail Transfer Protocol.

NTP, Network Time Protocol

A protocol built on top of TCP/IP that assures accurate local timekeeping with reference to radio, atomic or other clocks located on the Internet. This protocol is capable of synchronizing distributed clocks within milliseconds over long time periods.[FOLDOC].

PHP

PHP is a widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML. [PHPNET]

POP3, Post Office Protocol 3

Version 3 of the Post Office Protocol. POP3 is defined in RFC 1081, written in November 1988 by Marshall Rose, which is based on RFC 918 (since revised as RFC 937). POP3 allows a client computer to retrieve electronic mail from a POP3 server via a (temporary) TCP/IP or other[?] connection. It does not provide for sending mail, which is assumed to be done via SMTP or some other method [FOLDOC].

Secure File Transfer Protocol, SFTP

SFTP is a file transfer protocol which involves using an SSH server to manage the file uploads. It is secure in the sense that file contents are encrypted during transfer, and that plain-text passwords are never sent over the internet. SFTP is the logical successor to FTP, which is less secure, and more complex to firewall.

Sieve

Sieve is a language that can be used to filter email messages. It is a powerful language that provides a safe envirnment for filtering to occur during mail delivery, allowing messages to be delivered directly into mailboxes configured by the user.

SMTP, Simple Mail Transfer Protocol

A protocol defined in STD 10, RFC 821, used to transfer electronic mail between computers, usually over Ethernet. It is a server to server protocol, so other protocols are used to access the messages [FOLDOC].

SSH, Secure Shell

A Unix shell program for logging into, and executing commands on, a remote computer. ssh is intended to replace rlogin and rsh, and provide secure encrypted communications between two untrusted hosts over an insecure network. X11 connections and arbitrary TCP/IP ports can also be forwarded over the secure channel [FOLDOC].

SSL, Secure Sockets Layer

A protocol designed by Netscape Communications Corporation to provide secure communications over the Internet using asymmetric key encryption. SSL is layered beneath application protocols such as HTTP, SMTP, Telnet, FTP, Gopher and NNTP and is layered above the connection protocol TCP/IP. It is used by the HTTPS access method [FOLDOC].

TCP, Transmission Control Protocol

The most common transport layer protocol used on Ethernet and the Internet. It was developed by DARPA.

TCP is the connection-oriented protocol built on top of Internet Protocol (IP) and is nearly always seen in the combination TCP/IP (TCP over IP). It adds reliable communication and flow-control and provides full-duplex, process-to-process connections.

TCP is defined in STD 7 and RFC 793 [FOLDOC].

TLS, Transport Layer Security

A protocol designed to allow client/server applications to communicate over the Internet without eavesdropping, tampering, or message forgery.

TLS is defined in RFC 2246 [FOLDOC].

UDP, User Datagram Protocol

Internet standard network layer, transport layer and session layer protocols which provide simple but unreliable datagram services. UDP is defined in STD 6, RFC 768. It adds a checksum and additional process-to-process addressing information [to what?]. UDP is a connectionless protocol which, like TCP, is layered on top of IP.

UDP neither guarantees delivery nor does it require a connection. As a result it is lightweight and efficient, but all error processing and retransmission must be taken care of by the application program [FOLDOC].

URL, Uniform Resource Locator

A Uniform Resource Locator (URL) is a Uniform Resource Identifier (URI) that specifies where an identified resource is available and the mechanism for retrieving it. In popular usage and in many technical documents and verbal discussions it is often incorrectly used as a synonym for URI. The best-known example of a URL is the "address" of a web page e.g. http://www.example.com [WIKIPEDIA_URL].