The Coloured Book protocols were a set of

communication protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...

s for

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...

s developed in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

in the 1970s. The name originated with each protocol being identified by the colour of the cover of its specification document. The protocols were in use until the 1990s when the

Internet protocol suite The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the sui ...

came into widespread use.

History

First defined in 1975, they evolved through experience with the Experimental Packet Switched Service run by

Post Office Telecommunications Post Office Telecommunications was set up as a separate department of the UK Post Office, in October 1969. The Post Office Act 1969 was passed to provide for greater efficiency in post and telephone services; rather than run a range of services, ...

beginning in 1977. They were used on the SERCnet from 1980, and SWUCN from 1982, both of which became part of the

JANET Janet may refer to: Names * Janet (given name) * Janet (French singer) (1939–2011) Surname * Charles Janet (1849–1932), French engineer, inventor and biologist, known for the Left Step periodic table * Jules Janet (1861–1945), French psych ...

academic network from 1984. The protocols gained some acceptance internationally as the first complete X.25 standard, and gave the UK "several years lead over other countries". From late 1991,

Internet protocols The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

were adopted on the Janet network instead; they were operated simultaneously for a while, until X.25 support was phased out entirely in August 1997.

Protocols

The standards were defined in documents identified by the colour of the cover:

The Pink Book

The Pink Book defined protocols for transport over

Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...

. The protocol was basically

X.25 X.25 is an ITU-T standard protocol suite for packet-switched data communication in wide area networks (WAN). It was originally defined by the International Telegraph and Telephone Consultative Committee (CCITT, now ITU-T) in a series of drafts ...

level 3 running over LLC2.

The Orange Book

The Orange Book defined protocols for transport over local networks using the

Cambridge Ring (computer network) The Cambridge Ring was an experimental local area network architecture developed at the Computer Laboratory, University of Cambridge starting in 1974 and continuing into the 1980s. It was a ring network with a theoretical limit of 255 nodes (th ...

The Yellow Book

The Yellow Book defined the Yellow Book Transport Service (YBTS) protocol, also known as Network Independent Transport Service (NITS), which was mainly run over X.25. It was developed by the Data Communications Protocols Unit of the Department of Industry in the late 1970s. It could also run over TCP. The

Simple Mail Transfer Protocol The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typica ...

was extended to allow running over NITS. The Yellow Book Transport Service was somewhat misnamed, as it does not fulfill the Transport role in the OSI 7-layer model. It really occupies the top of the Network layer, making up for X.25's lack of NSAP addressing at the time, which didn't appear until the X.25 (1980) revision, and wasn't available in implementations for some years afterwards. YBTS used

source routing In computer networking, source routing, also called path addressing, allows a sender of a packet to partially or completely specify the route the packet takes through the network. In contrast, in conventional routing, routers in the network determ ...

addressing between YBTS nodes—there was no global addressing scheme at that time.

The Green Book

The Green Book defined two protocols to connect terminals across a network: an early version of what became Triple-X PAD running over X.25, and the TS29 protocol modelled on Triple-X PAD, but running over YBTS. It was developed by

. These protocols are similar in functionality to

TELNET Telnet is an application protocol used on the Internet or local area network to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection. User data is interspersed in-band with Telnet contr ...

The Fawn Book

The Fawn Book defined the Simple Screen Management Protocol (SSMP)

The Blue Book

The Blue Book defined the Network-Independent File Transfer Protocol (NIFTP), analogous to Internet

FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...

, running over YBTS. Unlike Internet FTP, NIFTP was intended for

batch mode Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically ...

rather than interactive usage.

The Grey Book

The Grey Book defined protocols for

e-mail Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic (digital) version of, or counterpart to, mail, at a time when "mail" meant ...

transfer (not file transfer as is sometimes claimed), running over Blue Book FTP.

The Red Book

The Red Book defined the Job Transfer and Manipulation Protocol (JTMP), a mechanism for jobs to be transferred from one computer to another, and for the output to be returned to the originating (or another) computer, running over Blue Book FTP.

Naming scheme

One famous quirk of Coloured Book was that components of hostnames used

reverse domain name notation Reverse domain name notation (or reverse-DNS) is a naming convention for components, packages, types or file names used by a programming language, system or framework. Reverse-DNS strings are based on registered domain names, with the order of the ...

as compared to the Internet standard. For example, an address might be user@UK.AC.HATFIELD.STAR instead of user@star.hatfield.ac.uk.

References

Sources

* *''A Dictionary of Computing''. Oxford University Press, 2004, s.v. "coloured book"

External links

alt.folklore.computers: "What is the British Grey Book protocol?"

Janet website
{{DEFAULTSORT:Coloured Book Protocols History of computing in the United Kingdom Network protocols Wide area networks X.25