[TUHS] networking on unix before uucp

[Jeremy C. Reed]

On Fri, 22 Aug 2014, Cory Smelosky wrote:

> How does that Berknet differ from the Berknet in...4.0/4.1BSD?  I've 
> seen what I THINK was ethernet code there...but I couldn't be sure as 
> I couldn't even decipher the addressing scheme. ;)
>
> I've been meaning to ask about Berknet, anyway.  One of my side 
> projects is to get it operational.

I have read most (if not all) of the berknet docs and a lot of the code. 
The docs and code referenced a rcs, rcsq, and rcslog as some tools that 
could be ran without a personal account on a remote system. I didn't 
recognize rcsq, but also these references pre-dated Tichy's alternative 
to SCCS by a year or so.

Then I realized this is "remote computer system link" used something 
like: rcsq to see queued jobs no sent yet for CDC 6400; rcslog to see 
history of jobs sent that day; and rcsrm to delete a job not sent yet. 
Basic concepts similar to berknet (netq, netlog, netrm).
(The clue I found was in 
http://www.eecs.berkeley.edu/Pubs/TechRpts/1979/ERL-79-16.pdf)

I know the Cyber 6400 was used there (some of my interviewees told me 
about it). Does anyone know if Berknet's design was inspired by this 
"rcs"?  Where can I learn more about it? (as searching for "rcs" is 
difficult)

I don't see any ethernet code in Berknet. The author had a summer job at 
XEROX PARC I think in the middle of his Berknet project and discussed 
the low-level network concepts with Boggs. Later, they considered an 
LNI, an early token ring (if I understand correctly), device, and DMC-11 
link, but I don't think berknet was ever extended for those or used 
using ethernet.

Note that extending Berknet probably didn't make sense. It was all 
batched with all the systems known to each system hardcoded, compiled 
in. Smallest jobs sent first from the queue to neighboring system which 
would send the job to next as if it was queued locally until it arrived 
to desired system.  So retrieving an email (box) or doing a remote copy, 
you would have to wait for the jobs to get ran. The speed on the 1200 
baud links was only around 50 characters per second. (I think at best on 
9600 baud links was around 600 characters per second but normally 350 
cps.) In addition, berknet had hardcoded restrictions limiting 100,000 
characters per single job. (It was later extended to 500,000 characters 
for some machines, then all machines while still limiting only 200,000 
characters max size jobs during day time.) (I never used berknet only 
read code and docs and did some interviews with users.) It was quite 
limited compared to the new real-time tools and near 3Mb network that 
started being developed and used there a couple years later.

By the way, the early berknet had a symlink to the batch remote copy 
netcp called "rcp" which predated Joy's real-time remote file copy, rcp, 
by a few years. The early version also included a trivial "sendmail" to 
remotely send mail over the batch berknet to another berknet system (by 
running "mail" on the remote system later). It predated Allman's 
unrelated intelligent mailer by around two years. The Berknet tool was 
replaced and renamed with "sendberkmail".