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Path: utzoo!watmath!clyde!burl!hou3c!gross@DCN9.ARPA
From: gross@DCN9.ARPA (Phill Gross)
Newsgroups: net.mail.msggroup
Subject: Estimate on number of Internet users
Message-ID: <8410261359.AA02821@dcn9.arpa>
Date: Fri, 26-Oct-84 09:59:16 EDT
Article-I.D.: hou3c.908
Posted: Fri Oct 26 09:59:16 1984
Date-Received: Sat, 27-Oct-84 04:21:57 EDT
Sender: ka@hou3c.UUCP (Kenneth Almquist)
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To: msggroup@brl.ARPA


I thought the message below might be of interest to arpanauts.  It
originated in the 'Human-Nets digest' (which I don't read) and was 
forwarded, with comments, to 'AIlist' by Ken Laws at SRI.  (Law's 
added comments are in square brackets.)  Any comments?

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Date: Wed, 10 Oct 84 01:50:10 edt
From: bedford!bandy@mit-eddie
Subject: Net Readership

     [Forwarded from the Human-Nets digest by Laws@SRI-AI.]

        Date: Mon, 8 Oct 84 14:28 EDT
        From: TMPLee@MIT-MULTICS.ARPA

        Has anyone ever made an estimate (with error bounds) of how
        many people have electronic mailboxes reachable via the
        Internet?  (e.g., ARPANET, MILNET, CHAOSNET, DEC ENET, Xerox,
        USENET, CSNET, BITNET, and any others gatewayed that I've
        probably overlooked?)  (included in that of course group
        mailboxes, even though they are a poor way of doing business.)

Gee, my big chance to make a bunch of order of magnitude
calculations.... [...]

USENET/DEC ENET: 10k machines, probably on the order of 40 regular
users for the unix machines and 20 for the "other" machines so that's
100k users right there.

  [Rich Kulaweic (RSK@Purdue) notes 15k users on 40 Unix machines
  at Purdue, with turnover of several thousand per year.  -- KIL]

BITNET: something like 100 machines and they're university machines in
general, which implies that they're HEAVILY overloaded, 100-200
regular active users for each machine - 10k users.

  [A news item in the latest CACM mentions 200 hosts at 60 sites,
  soon to be expanded to 200 sites worldwide.  A BITNET information
  center is also being developed by a consortium of 500 U.S.
  universities, so I expect they'll all get nodes soon.  -- KIL]

Chaos: about 100-300 machines, 10 users per machine (yes, oz and ee
are heavily overloaded at times, but then there's all those unused
vaxen on the 9th floor of ne43). 1k users for chaosnet.

I think that we can ignore csnet here (they're all either on usenet or
directly on internet anyway...), so they count for zero.

ARPA/MILNET: Hmm... This one is a little tougher (I'm going to include
the 'real' internet as a whole here), but as I remember, there are
about 1k hosts. Now, some of the machines here are heavily used
(maryland is the first example that pops to mind) and some have
moderate loads (daytime - lots of free hardware at 5am!), let's say
about 40 regular users per machine -- another 10k users.

I dare not give a guesstimate for Xerox.

  [Murray.PA@Xerox estimates 4000 on their Grapevine system.  -- KIL]

So it's something on the order of 100k users for the community. [...]
Well, it could be 50k people, but these >are< order of magnitude
calculations...

  [Mark Crispin (MRC@Score) notes that there are 10k addressable
  mailboxes at Stanford, but that the number of active users is
  perhaps only a tenth of this.  Andy's final estimate might be
  inflated or deflated by such a factor.  -- KIL]

Now that I've stuck my neck out giving these estimates, I'm awaiting
for it to be chopped off.

        andy beals
        bandy@{mit-mc,lll-crg}
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