- JANET NRS
The
JANET NRS (Name Registration Scheme) was a pseudo-hierarchical naming scheme adopted for use onUnited Kingdom academic and research networks before the superficially similar system used by the Internet DNS had been fully established.The principal difference was that the order of significance began with the most significant part (so called
Big-endian addresses). Also, NRS names were canonically written in upper case. For example, theUniversity of Cambridge had the NRS name UK.AC.CAM, whereas its DNS domain is cam.ac.uk. All NRS names had both a "standard" (long) and "abbreviated" (up to 18 characters) form. For example, UK.AC.CAMBRIDGE was the less widely used standard equivalent of the abbreviated name UK.AC.CAM.The NRS "second-level domains" consisted of UK.AC (JANET academic and scientific sites), UK.CO (commercial) and UK.MOD (Ministry of Defence). Any organisations not falling into these categories were given their own "second-level" name, eg. UK.BL (
British Library ) or UK.NEL (National Engineering Laboratory).For email, interoperability between the "Grey Book" email addressing style of user@UK.AC.SITE and Internet addresses of the style user@site.ac.uk was achieved by way of mail gateways. However, problems were caused when the least significant part of an Internet address matched the most significant part of an NRS address and vice-versa. (The classic joke was that e-mail intended for UK universities ended up in Czechoslovakia, since many JANET e-mail addresses were of the form user@UK.AC."universityname".CS, where "CS" stood for Computer Science (department), but "
.cs " was also the two-letter country code for Czechoslovakia until 1995.)JANET transitioned to using Internet protocols in the early 1990s, and the final mail gateway had been taken out of service by the end of
1997 . Its one remaining legacy is the convention of using.uk for UK based DNS domains, rather than.gb , as specified byISO 3166 .References
*cite conference
first = Jim
last = Reid
title = The Good Old Days: Networking in UK Academia ~25 Years Ago
booktitle = UKNOF7
date = 2007-04-03
location = Manchester
url = http://www.uknof.com/uknof7/Reid-History.pdf
accessdate = 2008-04-16
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