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Three levels of network infrastructure comprise the
whole of the Internet - Local Area Networks, Metropolitan
Area Networks and Wide Area Networks.
Local Area Networks
The Local Area Network (LAN) is that portion of the network to which
most computers are connected, and therefore it is the most familiar part
of the Internet. The speed of a typical LAN has grown
from 10 million bits per second (Mbps) to 100 Mbps in recent
years, and new hardware is now allowing expansion to a billion bits
per second (1 Gbps). In practical terms, this
means that a low-cost LAN has the capacity to provide
access to any service provided by machines on that LAN.
The question then becomes how far that LAN reaches, since its
scope, the more resources it is likely to have
available. Information Renaissance has worked to
develop architectures that extend the reach of a user's LAN
and encourage the sharing of local resources.
Specifically, Info Ren's "Smart Building" project created a
shared network environment in Pittsburgh's Regional Enterprise Tower,
a building donated by the Alcoa Corporation for the use of
nonprofit organizations working towards economic development.
The building's tenants share a common high-speed Internet connection.
Within the building, resource sharing is enabled through a fiber
optic backbone, with individual firewalls providing security for
each organization within the building. This
design permits every organization in the building to enjoy
the same level of peak Internet access, while paying only for
that portion of the external bandwidth actually used. The cost
for this type of service is an order of magnitude lower than
it would be if each organization were to purchase the service
separately from some external Internet service provider.
Metropolitan Area Networks
The concept of a Metropolitan Area Network (MAN) is less
familiar than a LAN: for
most people the MAN is invisible or is a weak point of their
Internet connection. MAN infrastructure was first provided
by dialup access over conventional telephone lines. More
recently telephone companies have offered higher speed
connections via technologies such as ISDN or DSL, both of
which use standard copper wiring to a home or office. Competing
with these services are cable modem connections offered by
cable television companies over their coaxial cable infrastructure.
DSL and cable modems represent efforts of incumbent telecommunications
companies to provide Internet service over an infrastructure that
was designed and deployed for a very different purpose. It is
therefore not surprising that these technologies have many built-in
limitations in both availability and cost. Information
Renaissance worked as a pioneer in the use of these technologies.
More recently, we have sought technologies that are better suited
to providing high-speed Internet access, including both fiber optic
cabling and new wireless technologies.
Info Ren believes that future MAN infrastructure should be designed
and deployed by municipalities in much the way they design and
deploy streets, water and sewer systems. That is, this infrastructure
should reach everyone, should be designed for economies of scale and
should be maintained as a public utility. This ideal may be
hard to reach, given the political power of the incumbent
service providers, their dependence on expensive legacy facilities
and the reluctance of municipal government to assume responsibility
for new services. Nonetheless there are many steps that
cities and towns can take in this direction, such as to encourage
the installation of conduit when city streets are built or rebuilt,
and to plan municipal telecommunications with an eye toward shared
infrastructure.
Groups of organizations can also
create their own network infrastructure. Wireless technologies
require access to towers or rooftops for the placement of
antennas, but they do not involve digging up streets or
stringing wires on utility poles. This makes it
possible to deploy wireless networks very quickly and at
a cost much lower than that of wired infrastructure. In
recent years the speeds of such services have lept far ahead
of services provided over copper wire (including ISDN, DSL
and cable modems), and their cost has plummeted.
Info Ren is working with community groups in Pittsburgh
to form a cooperative that will manage a city-wide wireless
network. As with the Smart Building project, members will
enjoy shared access to a common Internet connection, high-speed
access to resources on the wireless network, shared user
support and very low monthly fees. Indeed, the working
model of this network is to provide performance equal
to that of a Local Area Network, but across the broader region
of a Metropolitan Area Network.
Wide Area Networks
The Wide Area Network (WAN) refers to that part of the
Internet that extends beyond one's own community. For most
users it is harder to influence the structure and operation
of this larger network. Yet some aspects of local network
performance may depend upon the way in which one's
MAN is connected to the WAN infrastructure. Local interconnections
are a key issue here. Many Internet
providers prefer to carry traffic on their own networks
as far as possible and provide interconnections with other
carriers at their own convenience. This can lead to
bizarre situations in which network traffic from one side
of a street to the other may travel hundreds of miles across
ten different states before reaching its destination. People
typically discover these situations when their network
service is slow and unreliable. Information Renaissance
seeks to inform those we work with of network design issues
of this sort and help them select Internet providers capable
of providing the best service at the lowest possible cost.
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