56 Networking Explained, Second Edition
1. Please begin by deﬁning the Internet.
OK. We’ll try. Deﬁning the Internet today is a bit more problematic, though, than it was
several years ago. Its deﬁnition varies from person to person. For example, during its early
years, the Internet was deﬁned as a collection of computer networks based on a speciﬁc set
of network standards, namely, TCP/IP. This was the deﬁnition we gave in Chapter 1. Other
users, however, whose focus might be on the information they have acquired or the people
with whom they have communicated, might deﬁne the Internet as a global collection of
diverse resources, or as an electronic community of people. In fact, compared to the Inter-
net’s early days, some people have commented that the Internet has been transformed
from a community of networks to a network of communities. Still others, whose only
experience with the Internet is using the World Wide Web, might say the Internet and
World Wide Web are synonymous and hence the Internet is the World Wide Web. Conse-
quently, deﬁning the Internet is a function of perspective. Regardless of the deﬁnition or
perspective, the Internet interconnects individual, autonomous computer networks and
enables them to function and appear as a single, global network.
2. How did the Internet get started?
The Internet’s roots can be traced back to 1957 when the United States formed the
Advanced Research Projects Agency (ARPA) within the Department of Defense (DoD).
The formation of ARPA was the United States’ response to the former Soviet Union’s
launch of Sputnik, the ﬁrst artiﬁcial earth satellite. ARPA’s mission was to establish the
United States as the world’s leading country in defense- and military-applicable science
and technology. ARPA, which later became known as Defense ARPA (DARPA), estab-
lished in 1969 an early internetwork called ARPANET, the Advanced Research Projects
Agency Network. The builder of ARPANET was a company named Bolt, Baranek, and
Newman, which later became known as BBN Communications. Originally, the Internet
meant ARPANET, and access to ARPANET was restricted to the military, defense contrac-
tors, and university personnel involved in defense research. ARPANET technology was
based on packet-switching, and in 1969, with the connection of its ﬁrst four nodes—Stan-
ford Research Institute (SRI), University of California at Santa Barbara (UCSB), Univer-
sity of California at Los Angeles (UCLA), and University of Utah—ARPANET heralded
the era of packet-switching networking.
3. I recall that the university I attended had a BITNET connection. Was this similar
Not quite. BITNET, which stood for Because It’s Time Network, was a low-speed and
inexpensive academic network consisting of interconnected IBM mainframes. BITNET
was one of several cooperative, decentralized computer networks that formed in the late
1970s and early 1980s on college and university campuses to serve the academic commu-
nity. Using a proprietary IBM-based network protocol, BITNET connectivity was via
9600 bps leased circuits and was based on the store-and-forward principle. Networking
services available via BITNET included ﬁle transfer, e-mail, and an IBM application
called remote job entry (RJE). In an RJE environment, small processors located at remote
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