Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!rice!uw-beaver!mit-eddie!bbn.com!mckenzie
From: mckenzie@bbn.com (Alex McKenzie)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: IP and Coloured Book Software in the UK
Message-ID: <64824@bbn.BBN.COM>
Date: 24 Jun 91 13:39:40 GMT
References: <23676@shlump.lkg.dec.com>
Sender: news@bbn.com
Reply-To: mckenzie@labs-n.bbn.com (Alex McKenzie)
Organization: Bolt Beranek and Newman Inc., Cambridge MA
Lines: 36


Mark Crispin and Dan Lynch have already stated the official NCP to
TCP/IP transition date.  They have correctly stated the mad rush at the
end of 1982 to make the cutover.  For the historically curious, here are
a few more facts.

The first TCP implementation I am aware of was for the PDP-10 running
the TENEX operating system; it was reported to be running at BBN in
February 1975.  By November 1975 this implementation had been involved
in experiments with a Stanford University implementation for the PDP-11.
The experiments disclosed protocol design deficiencies which resulted in
a revision of the TCP spec.

The first TCP implementation for UNIX was written at BBN; it reached
operational status by November 1977.

A TCP/IP gateway written by BBN for the PDP-11/40 was in use
interconnecting the ARPANET and the Packet Radio Network (a DARPA
project) by May 1978.

The RFC announcing that the official cutover from NCP to IP would be
1/1/83 was published in November 1981, allowing more than a year for
host organizations do do planning and implementation.  There were TCP/IP
implementations for most ARPANET hosts already running (in at least
prototype form) by November 1981.

About 1/3 of the 285 general-purpose ARPANET hosts accepted TCP
connections in early December 1982, about 1/2 in early January 1983, and
about 2/3 by the end of February 1983. The IMP (packet switch) code
which would disable transmission of NCP protocol traffic was actually
never activated, although it had been written, tested, and installed.

Cheers,
Alex McKenzie
BBN Laboratories