From: jdg41088@uxa.cso.uiuc.edu (Pickaxe)
Subject: Re: How many people are on the net?
Organization: University of Illinois at Urbana
Date: Wed, 30 Dec 1992 08:08:14 GMT

ss@panix.com (Steve Steinberg) writes:

>In <C0179q.DtJ@news.iastate.edu> jerrett@iastate.edu (Gregory A Jerrett) writes:

>>I have been curious about this for some time.  Is there a rough estimate
>>out there anywhere of the approximate number of peopele/people who are 
>>hooked up to the internet?

>A recent NY Times article said 3+ Megapeoples.

This may be much more of an answer than you really expect, or want for that
matter but here goes. 

Reprinted from UIUCnet, the University of Illinois campus network newletter,
Nov 1991. vol 4, no 4.

******************************************************************

                  HOW BIG IS THE INTERNET?

How big is the Internet?  How many people use it and exactly how 
is it used?  These are some of the common questions asked by new 
and even experienced users as they ponder this vast and sometimes 
overwhelming resource.  Unfortunately, there are no simple or even 
direct answers.  How does one measure an internetwork consisting 
of thousands of local, regional, mid-level and national networks 
whose numbers are constantly growing and whose topologies are 
constantly evolving--a "super-network", the management and 
administration of which are so decentralized that some writers 
have dubbed it "anarchy-net."  Although there is no single 
authority to turn to for all the facts and figures about the 
Internet, with the help of statistics gathered by  organizations 
like the Network Information Center of the Data Defense Network 
(DDN NIC) and Merit Incorporated (Operations Center for the 
National Science Foundation Network [NSFNET]), we can at least 
begin to take measure of this elusive network of networks.


How Many Networks?
------------------
One way to measure the Internet is to count the number of separate 
networks it comprises.  Every TCP/IP network on the Internet has a 
unique network address that must be obtained from a central 
addressing authority, the DDN Network Information Center (for more 
information on the DDN NIC, see the article and sidebar on page 
3).  As of September 1991, the NIC had allocated nearly 37,000 
network IP addresses.  Not all of these networks, however, are 
connected to the Internet.   All organizations with TCP/IP 
networks are encouraged to get their network numbers from the NIC 
regardless of whether they plan to be connected to the Internet or 
not. The greater part of this number actually represents private 
TCP/IP networks without Internet connectivity.  When asked how 
many of the 37,000 were actually part of the Internet, a NIC 
representative reluctantly came up with the number 10,660 and 
called the figure a "moving target" at best,  because new networks 
are constantly being added to the register, and, more 
problematically, occasionally large blocks of network addresses 
are allocated to organizations that in turn reallocate them.  The 
status of these blocks of addresses is unknown to the NIC.

We also know the number of networks expressly configured to access 
the NSFNET national high speed T1 and T3 backbones. According to 
Merit Inc., which has been maintaining statistics in this area for 
many years, 516 networks announced their routes on the T1 in May 
of 1989.  By May of '91 the figure had increased to 2,763, and in 
October of this year the count was 3,556 on the T1 and another 869 
on the faster, but less stable T3 backbone.


How Many Hosts?
---------------
While it is possible to specify with relative accuracy the number 
of networks with Internet connectivity (or at least NSFNET 
connectivity), the question of how many hosts (individual 
computers with unique IP addresses) make up those networks is more 
difficult to answer.  The absence of concrete data in this area is 
due to the fact that the registration of new hosts on a TCP/IP 
network is largely a matter of local concern.  For example, when a 
new computer is attached to UIUCnet, the host name and IP address 
of the computer is registered with the host manager at CSO.  The 
host manager adds the information to several tables, and the 
process more or less ends there.  There is no national database 
containing the name and IP address of every host on the Internet 
and thus no effective method of counting every host on every 
network.  We do know, however, the minimum number of hosts on the 
Internet as of October of this year.  An Internet Domain Survey 
conducted by SRI International (former home of the DDN NIC) 
reported no fewer than 617,000 individual IP hosts (as compared 
with approximately 30,000 in April of 1988).  If this number seems 
large, even more astonishing is the rate at which the number of 
hosts has been growing in recent months. According to the same 
survey, the number of hosts increased by 100,000 over the three 
month period of July through September 1991 (or roughly 1000 hosts 
per day).


How Many Users?
---------------
Some Internet hosts are single user machines like PCs, Macs and 
engineering workstations.  Others are multi-user minis or 
mainframes that can provide Internet access to tens, hundreds, or 
even thousands of users (the CSO Unix mainframe uxa, for instance, 
offers access to over 11,000 University of Illinois students).  At 
the other extreme are hosts that do not provide any direct end-
user access such as those dedicated to the tasks of routing 
traffic, gathering statistics, or performing other basic network 
functions.  Thus behind each host there could be anywhere from 
none to thousands of users.  Compounding  the problem is the fact 
that there are many commercial, private, and restricted networks 
that offer  limited  access to the Internet  (or  to regional 
networks attached to it).   Should individuals on these networks 
also be counted among the ranks of bona-fide Internet users?  In 
short, nobody knows for certain how many users can access the 
Internet, but whether the users with limited access are included 
or not, it's probably safe to say that the number is, at the very 
least, many times greater than the number of connected hosts.


How Many Packets?
-----------------
As the number of Internet networks, hosts, and users grows, so too 
does the network traffic they generate.  For the last four years, 
Merit Inc. has been counting both "packets"  (the basic unit of 
information sent across a TCP/IP network) and bytes as they are 
passed onto and off of the NSFNET backbones.  During the month of 
September 1988, 202 million packets were passed onto the T1 
backbone.  By September of '89, the number had increased to 1.5 
billion packets per month and a year later the number had leapt to 
4.5 billion per month.  September '91 packet counts for both the 
T1 and T3 backbones were around 8.5 billion and 2 billion 
respectively, nearly  fifty times the traffic of four years ago.  

In September, Merit also began keeping track of the origins of 
packets traversing the T1.  Merit's breakdown by country during 
the month of September shows that 87% of the backbone traffic was 
generated by 1758 different networks in the United States.  
Another 3.3 percent of the traffic originated in Canada.  In 
total, 2,958 networks from at least 33 countries sent packets 
across the T1 backbone during this one month period.


How Is It Used?
---------------
Of the data gathered by Merit, perhaps most interesting are the 
figures on how the network is used.  In May of 1991, Merit 
released information on the most frequently used NSFNET 
applications based on packet and byte counts.  The results are 
shown in  figure 1.  Both in terms of packets and bytes, file 
exchange (ftp) predominates, with electronic mail running a close 
second. Interactive applications (remote login with telnet) 
account for 17% of the packet count but only 6% of the byte count.  
This apparent discrepancy can be explained if we understand that 
TCP/IP packets can hold variable lengths of data.  During a telnet 
session, characters are sent to and from the remote host one at a 
time, so that the data area of each packet typically contains just 
one byte.   Thus, the packet overhead of telnet sessions is high 
while the number of bytes transmitted is comparatively low.  
Applications like ftp (the TCP/IP file transfer utility), on the 
other hand, pack as much data into each packet as possible, 
requiring fewer packets with higher byte counts to accomplish 
their task.


Still Growing After All These Years
-----------------------------------
How big is the Internet? As the foregoing has shown, by any 
measure, it is rapidly increasing in size.   Its staggering growth 
rate is such that even if one could obtain precise statistics on 
the  number of users, hosts, and networks connected to it at any 
given moment, they would undoubtedly be outdated before they could 
be published. 

-Lynn Ward

*********************************************************************

-- 
| Joe Gross          | Department of Electrical and Computer Engineering |
| pickaxe@uiuc.edu   | University of Illinois at Urbana-Champaign        |
| (217) 328-4331     | "I've given up trying to stay ahead of the times, |
| NeXTmail welcome   | it's now a matter of how far I get left behind."  |
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