[ih] NCP and TCP implementations

Karl Auerbach karl at cavebear.com
Tue Mar 10 10:04:27 PDT 2020


I have a somewhat vague memory of a University of Illinois 
implementation dating from the mid-to-late 1970's.

I mostly remember that it ran on Unix and thus was probably written in C.

It had a large daemon (that contained most of the protocol code) and a 
small daemon (that mainly listened for incoming connections and exec-ed 
itself to become the large daemon.)

I had most direct interaction with it at some gov't offices (DoD 
related) in Reston, VA.

The Dave Clark/MIT one was perhaps the PC/IP one written by John Romkey 
and Dave Bridgham?  That was nearly all in C.  Some tiny parts (such as 
the code that did an audio chirp in its telnet client) were in assembly 
language.   That TCP implementation was constructed on the assumption 
that its only application would be a human typing on a telnet session, 
so it simplified the code by ignoring the offered receive window on the 
assumption that a human could never type fast enough to fill whatever 
window was offered. That's why it had to be re-written (again, in C) 
when it it became PC/TCP from FTP Software.

         --karl--





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