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From: jsq@ut-sally.UUCP (John Quarterman)
Newsgroups: net.lan
Subject: Re: Xerox NS or Courier for UNIX?
Message-ID: <355@ut-sally.UUCP>
Date: Tue, 8-Nov-83 21:45:58 EST
Article-I.D.: ut-sally.355
Posted: Tue Nov  8 21:45:58 1983
Date-Received: Wed, 9-Nov-83 22:23:55 EST
References: <1668@fortune.UUCP>, <478@cbosgd.UUCP> <1897@gatech.UUCP>
Organization: U. Texas CS Dept., Austin, Texas
Lines: 43

I was hoping somebody else would follow this up, but since nobody has:

>The TCP/IP protocol (which I know the least about, so if I make a mistake,
>please forgive me) is formulated by the National Bureau of Standards and is
>blessed by the Defense Department.  I'm not sure if it covers all the layers
>of the ISO model.  Because of the DoD blessings, many companies are at least
>implementing gateways to TCP/IP.

TCP/IP is not one protocol, but two:  IP (Internet Protocol) is the top
of ISO's network layer (3) and handles internet addressing, among other
things;  TCP (Transmission Control Protocol) fits in ISO's transport
layer (4) and handles fragmentation/reassembly, process-host/process-host
reliable connections, etc.  There is a datagram protocol called UDP
that can be used on top of IP in place of TCP.

TCP/IP was developed for the Defense Advanced Research Projects Agency
by numerous research institutions, such as BBN, Rand, ISI, Berkeley, etc.
on the ARPANET over many years.  Work continues, mostly being conducted
via the ARPA Internet.  The National Bureau of Standards has adopted
TCP/IP in the last few years (though they've changed their version somewhat).

TCP/IP and related protocols do cover all the ISO layers, though they
were developed under a different reference model than the ISO one.
The ISO model is a later one built partially on ARPANET experience,
but with somewhat different goals and perspectives.  There is a paper
on this subject by M.A. Padlipsky, "A Perspective on the ARPANET
Reference Model," that might be of interest.

The reason for the increasing industry use of TCP/IP is not so much
DoD blessings (more of a curse to many), but the plethora of existing
implementations of TCP/IP.  There are currently about 130 registered
networks and 780 hosts in the ARPA Internet, all running TCP/IP.
This may not seem impressive compared to the 1600 odd UUCP sites, but
the quality and variety of service is several orders of magnitude better.
The underlying physical networks include ARPANET-style (BBN 1822) networks,
ethernets, and token rings.  The host machines and operating systems
are too numerous to mention.

In other words, it's been around longer than most anything else,
it has great adaptability, and it works.
-- 
John Quarterman, CS Dept., University of Texas, Austin, Texas
{ihnp4,seismo,kpno,ctvax}!ut-sally!jsq, jsq@ut-sally.{ARPA,UUCP}