Not every product we used today was planned out perfectly
from the start. It is often the case that products are discovered accidently,
or the way they are used commercially have nothing to do with the original intent
of the products creator. Famous examples of this are things like the slinky
toy, x-rays, and the microwave. Each of these inventions were created during
research and engineering efforts to solve other problems. The slinky came into existence
when an engineer dropped a large industrial spring, x-ray imaging and the
microwave were both invented while researching radio waves. There are other
instances where a byproduct or quick fix action ends up becoming a prominent feature
of a system. Two technologies that fit this description are Network Address
Translation (NAT) and Short Message Service (SMS) text messaging.
Network Address Translation
To understand the accidental impact of NAT, we must first briefly
review the history of the Internet. The Internet that we use today was first
developed as a communications network for the United States military. The Advanced
Research Projects Agency (ARPA) built ARPAnet in 1969 as a way to connect military
mainframe computers together. The original addressing scheme for ARPAnet was 8
bit and allowed for 256 different host addresses. The original ARPAnet started
with 4 hosts and quickly grew to 213 hosts by 1981 (Bort, 1995).
Realizing the limitations of the ARPAnet addressing scheme, Robert Khan and
Vinton Cerf started working on a new addressing scheme. The fourth iteration of
their work produced IPv4 addressing. IP stands for Internet Protocol and v4 is
the fourth version they created. IPv4 is a series of 4 8 bit addresses that can
support 4,294,967,296 unique addresses (Bort, 1995).
This version was a tremendous upgrade from the original 256 possible supported
hosts, but due to the rapid expansion of the Internet in the 1990’s, the mismanagement
of address allocation, and other technical issues with routing and traffic
management, the Internet was facing a real problem or running out of space that
needed to be addressed. IPv4 address space was very large and there needed to
be a way to route traffic to the appropriate networks around the Internet. The original
solution was to build classes into the address space. IPv4 classes are simply a
way to identify the size of a network based on the first 8-bit value in the
address. The classes were broken up into 4 classes:
·
Class A –
o
First bit value of 0 – 127
o
126 networks with 16,777,214 hosts each
·
Class B –
o
First bit value of 128 – 191
o
16,384 networks with 65,534 hosts each
·
Class C –
o
First bit value of 192 – 223
o
2,097,152 networks with 254 hosts each
·
Class D & E –
o
First bit value of 224 – 255
o
Used for multicasting and R&D
This wasn’t a perfect solution because the amount of
addresses per class were not scalable. For example, there are only 126 class A
networks that could be given out, and each one had almost 17 million usable
hosts. There are over 2 million class C networks that can be given out, but
each one only has 254 available hosts. During the 1990’s, many large companies were
given class A networks and didn’t use anywhere near the amount of hosts they
had available, so those addresses were essentially lost. Meanwhile, smaller
companies grew and required more and more class C networks as their demand for
hosts increased. The class C networks weren’t given out in sequence, so
companies had network addresses that weren’t mathematically close to each other,
which increased the difficulty of routing Internet traffic. The problem was
quickly becoming unmanageable.
IPv6 was developed to expand the total address space for the
Internet. It could support 340,282,366,920,938,463,463,374,607,431,768,211,456
total addresses (Loshin, 2001)!
The problem was that IPv6 wasn’t drafted until 1998 and it was taking much too
long to become a standard. A temporary solution needed to be found. NAT was developed
to temporarily solve the issue with lack of address space but ended up solving
many other issues that it essentially delayed the IPv6 rollout of IPv6 for
almost 14 years! NAT is a protocol that runs on a router that borders an
internal network and the Internet (Trowbridge, 1997). What NAT does is simply translate IP addresses
on the internal network with IP addresses being used on the Internet. The
feature that makes NAT so useful is that this translation can be one to many. This
means that an organization can host multiple systems internally while only
using one address to access the Internet. NAT adds information into the header information
of network traffic that is used to assign that traffic an internal and external
IP address to use. This way one external IP address can be used to provide
Internet connectivity to multiple hosts. NAT inadvertently solved many of the
problems with IPv4. Since IPv4 addresses could be reused internally, corporations
only needed a few valid IP addresses to provide Internet connectivity to all their
hosts. NAT averted the risk of running out of addresses so successfully that
IPv6 could be delayed for years with almost no repercussions. This allowed IPv6
development to continue and provided a very robust addressing solution that should
allow for sustainable address space for years to come. There were several other
factors that dealt with IP addressing that contributed and augmented NAT, such
as Classless inter-domain routing, that can be explored to provide a more detailed
picture as to how NAT helped change the way the internet worked.
Text Messages
Text messaging has quickly become the standard way of communicating
with mobile phones over the last 15 years, and it wasn’t a feature that was
planned to be used for commercial use at all. Telephone lines have historically
been analog systems, which means that they use waveforms to transmit voice and data
instead of digital data such as bits. Early telephone systems handled all
aspects of the call using signals that could be sent through the same wires that
were used to send the voice waveforms. For example, phones ring by having a
telephone switch send a higher than normal amount of electricity to the phone, which
used to activate an electro-magnetic bell in the phone and made the phone ring.
As telephones and telephony systems became more complex, the signals passed on
the wire did as well. The signaling data eventually had to move off the voice
transmission lines, and onto separate lines for management, which is called
out-of-band signaling. Large phone switches would communicate things like
timing, line availability, and other management information over out-of-band
signaling. In 1984 Friedhelm Hillerbrand and Bernard Ghillebaert realized that
this signaling traffic wasn’t always being used (Kuerbis, van Stolk-Cooke, & Muench, 2017). They developed a way to send
ASCI characters along the signaling lines when they were not being used, which
let them send text messages from phone switches to end users. The signaling formats
that would send the messages could only support messages of 128 characters at a
time, and both Hillerbrand and Ghillebaert believed that end users would only
be able to acknowledge the message. Global System for Mobile communications
(GSM) met in 1985 and started the process of developing the concepts behind Short
Message Service (SMS), which is the standard used to send text messages. Since
all phone traffic requires signaling data, providers could give text message
access to their customers while incurring almost no cost developing or
implementing the service. They were simply using a resource they already had in
a different way.
SMS allowed for broadcasts to phone, like Hillerbrand and
Ghillebaert first envisioned, but also point to point messaging between phones.
SMS messaging was first commercialized by Nokia in 1994 and gained popularity
with the advent of smart phones like the iPhone. In 1999 text messaging between
networks became possible and SMS messaging dramatically increased. The average
mobile phone user sent about 35 text messages a month in 2000, by 2010 200,000
text messages were being sent every minute, and over 6.1 trillion texts were sent
that year(Steeh, Buskirk, & Callegaro, 2007)! Text messaging packages with
cellphones started as an expensive perk and are now a necessity for any phone
plan. Text messaging remains one of the largest examples of companies charging
customers premium prices for a service that cost them almost nothing to implement.
It has also become the de facto way to communicate today and it was never intended
for that use!
References:
Bort, J. (1995). The address mess. InfoWorld, 17(46), 75.
Kuerbis,
A., van Stolk-Cooke, K., & Muench, F. (2017). An exploratory study of
mobile messaging preferences by age: Middle-aged and older adults compared to
younger adults. Journal of Rehabilitation
and Assistive Technologies Engineering, 4, 2055668317733257. doi:10.1177/2055668317733257
Loshin,
P. (2001). Network address translation. Computerworld,
35(8), 60.
Steeh,
C., Buskirk, T. D., & Callegaro, M. (2007). Using Text Messages in U.S.
Mobile Phone Surveys. Field Methods, 19(1),
59-75. doi:10.1177/1525822x06292852
Trowbridge,
D. (1997). A natty solution to a knotty problem. Computer Technology Review, 17(2), 1-1,6+.
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