Path: utzoo!attcan!uunet!dino!hascall
From: hascall@cs.iastate.edu (John Hascall)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Are Commercial TCPs Berkeley Code Or Custom?
Message-ID: <2361@dino.cs.iastate.edu>
Date: 30 Jul 90 14:46:37 GMT
References: <32140@cup.portal.com>
Sender: usenet@dino.cs.iastate.edu
Organization: Project Vincent, Iowa State University Computation Center
Lines: 24

In article <32140@cup.portal.com> Will@cup.portal.com (Will E Estes) writes:

}Are most of the commercial TCP/IPs sold by companies like Wollongong, Excelan,
}and FTP software written from scratch, or is the code basically just modified
}Berkeley code?  Why is it so difficult to write a good TCP/IP?
		 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   Try it sometime!!  It has taken me over a year of evenings (as many as
my wife will stand for :-) to put together a good solid ARP,IP,ICMP,UDP,TCP,DNS
under VAX/VMS (working entirely in assembly doesn't help!).  And that still
leaves all the "user" stuff (Telnet, FTP, etc...).  [And since the arrival
of 300+ DECstations, VAXes look to be dead here soon, sigh.]

   A big part of the difficulty is all those RFCs -- if you have a working
implementation and a new "good thing" comes out, it is usually not that hard
to add it (unless of course your code looks nothing at all like BSD's :-(
but to try to get all of those things working while more are being thought-up
every day is rather a losing battle.

   By my estimation, most (at least half) of the difficulty is in TCP.
The other half was reverse-engineering DEC's "backdoor" into the ethernet
driver.  Leaving the rest as the third half.

John Hascall  /  john@iastate.edu  /  hascall@atanasoff.cs.iastate.edu