Technical Design
To enhance the University of Wyoming’s research competitiveness, several
alternative network engineering plans were considered. Design criteria included
overall cost, expandability, reliability, quality of service considerations, and
isolation of regional traffic from national backbone networks.
The resulting network plan represents an initial design based on current costs
and available commercial offerings. This design recognizes the long distances
between Laramie, ISP points-of-presence, and our potential gigapop site at NCAR
We noted that the bit rate of ATM service can be regulated to provide specific
traffic capacity. Thus UW may require only 10 Mbps initially but may later require
full DS-3 or OC-3 capacity. This growth can be accommodated easily using ATM with
minimal additional equipment (however ATM port connections and access circuits
will need to be upgraded to achieve certain bit rates). ATM also supports multiple
data streams (i.e., permanent virtual circuits or PVCs) and thus commodity as well
as meritorious Internet traffic can be multiplexed over a single interface. ATM
also provides a cost-effective way to serve multiple sites through a single
network access interface at a regional gigapop. Furthermore, end-to-end ATM
connections have the capability of providing QoS for delay sensitive applications.
We also noted that the cost of ATM service is distance insensitive and thus
potentially offers a flexible and cost effective way to connect to a high-speed
national backbone network. For these and other reasons, ATM was utilized to
connect UW to a network ISP and a regional gigapop.
Unfortunately, the network infrastructure in the state of Wyoming is limited
and direct connection to public ATM networks is not yet available in Laramie.
National network companies offer connection to their public ATM networks by
utilizing back-haul access circuits to their nearest ATM POP. The cost of the
back-haul circuit is significant and is approximately equal to the cost of public
ATM service. This is a significant problem for the University of Wyoming. The
nearest point-of-presence (POP) for a major network provided is in Cheyenne which
is approximately 50 miles from Laramie. Thus we are faced with the need for a long
back-haul access circuit that is priced on a mileage basis. Compounding the
problem is the fact that only US West can provide the back-haul access circuit and
thus we do not benefit from vendor competition.
In the future we hope to see expanded public ATM offerings which may allow the
elimination of the mileage sensitive (back-haul) access circuits. For example, it
is our understanding that US West is working toward meeting FCC and PUC
requirements for carrying inter-LATA traffic. Also, we are encouraging network
providers to establish a POP in Laramie, possibly with seed money provided by the
State of Wyoming. In the meantime all long-distance data, voice, and video traffic
must first be back-hauled to Cheyenne. The University of Wyoming currently pays
for multiple T-1 circuits between Laramie and Cheyenne; one T-1 for an Internet
connection via SprintLink and five T-1 circuits for long-distance voice circuits
to major Inter-eXchange Carriers (IXC). We plan to install a private wide area ATM
network which will provide replacement for the leased T-1 circuits and provide
future expansion capabilities including access to the Internet at speeds up to
OC-3. This network is described in figure 2 below.
Figure 2 – Planned UW ATM Wide Area Network
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