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Appendix
A: Network Description
Phase
1: Initial Network Build
The initial network uses OC-3 microwave radio
and leased Bell Atlantic services to provide a redundant network,
as graphically shown in the attached figures. The network
has following main properties:
General:
- The design provides a redundant in-county network and
a redundant egress network.
- The primary transport mode for the network is OC-3 microwave
technology and leased DS3 circuits from Bell Atlantic. The
leased fiber needs of the network are very limited, and,
with the exception of a short 200’ aerial build, no fiber
builds are required. As such, it is expected that this network
is fully realizable and can be implemented in the very near
term without technical or physical limitations.
- The network is based on ATM cell technology as compared
to traditional TDM (Time Division Multiplex) technology
thereby providing the following advantages:
1. Ability to concentrate
and compress traffic to provide more effective utilization
network bandwidth
2. The ability to reroute traffic
in the event of a failure over diverse media (fiber
or copper)
3. The availability of enhanced
end-user services including native LAN services. |
- The leased DS3 circuits are bottlenecks of the backbone
network. With the use of ATM technology, the DS3 links can
be over-subscribed to a 10:1 ratio. The traffic models used
here use a conservative estimate of 6:1 over-subscription
on links prior to implementing network bandwidth enhancements
(e.g., fiber builds or leased fiber). The actual throughput
depends on the mix of end customer traffic and the types
of services carried.
Hub Sites:
- An important component of the Phase 1 network is the
establishment of hub sites at each main town within the
in-county network. Each hub provides a telecom equipment
room that is approximately 2000 sq ft with appropriate power,
generator, UPS, and HVAC. These hub sites provides convenient
and optimized locations for customers and service providers
to collocate with Berkshire Connect to gain access to the
Berkshire Connect network.
- The existence of service providers within Berkshire Connect
hubs will foster the proliferation of enhanced and basic
telecom services within the county. These services could
include ISP services, video conferencing services, data
storage services, enhanced voice mail services, and access
to long distance carriers and top tier ISPs.
In-County Network:
- The in-county backbone network is a ring consisting of
an OC-3 radio link between N. Adams and G. Barrington (via
Mt. Greylock) and leased DS3 facilities (via Bell Atlantic)
between G. Barrington and Pittsfield and between Pittsfield
and N. Adams.
- Within the in-county network, the network uses virtual
collocation at Bell Atlantic central offices (COs) to minimize
the costs associated with DS3 transport and also to reduce
the costs associated with local access to end-customers
via Bell Atlantic local loops (i.e., dedicated DS1s to end-customer
through Bell Atlantic).
- Virtual collocation will exist in Bell Atlantic COs in
N. Adams, Pittsfield, and G. Barrington.
- SONET transport equipment will be used to link Berkshire
Connect hub locations to the BA Central Offices.
Egress Network:
- The egress backbone network is a ring consisting of an
OC-3 link between N. Adams and Springfield and a leased
DS3 from Pittsfield to Springfield. Connectivity between
Pittsfield and N. Adams is provided as part of the in-county
network. The N. Adams to Springfield span consists of microwave
radio links to Mt. Tom in Holyoke and leased dark fiber
from Bell Atlantic into Springfield.
- Within Springfield, it is suggested that Berkshire Connect
use physical collocation at the Bell Atlantic central offices.
The reasons are:
1. Physical collocation will
minimize the transport costs associated with the DS3
circuit from Pittsfield and the costs associated with
the leased fiber strands between Mt. Tom and Springfield.
2. Physical collocation will minimize the costs
of interconnecting with other carriers for those carriers
currently collocated with Bell Atlantic in this office.
3. The alternative, which is for Berkshire
Connect to establish an equipment facility with a third
party, it is not expected to provide lower rates nor
provide increased flexibility for interconnection with
other carriers. |
Local Access
- The primary means for providing local access within the
county will be through the use of Bell Atlantic local loops
and through collocation of end-users at Berkshire Connect
hub sites.
- There may be an opportunity as part of Phase 1 to provide
fiber connectivity to "cluster areas", such as
office parks or dense business locations, if fiber is available
to do so.
Phase 2: Fiber Upgrades
Phase 2 is actually three independent fiber
upgrades that will be implemented independently to replace
DS3 leased capacity from Bell Atlantic with OC-3 transport.
Graphical views of the fiber upgrades are provided in the
attached figures.
The upgrades are:
- Upgrade #1: Bike Path Upgrade: The DS3 link from Pittsfield
to N. Adams will be replaced with a fiber span along the
soon-to-be constructed bike path from the Lanesborough/Pittsfield
line to Adams center. Given that the construction of the
bike path will be done in 1999, it is suggested that the
fiber build also be implemented in this timeframe to reduce
costs.
- Upgrade #2: Fiber Upgrade G. Barrington to Pittsfield:
This fiber upgrade would provide for a buried fiber cable
along existing rights-of-way between Great Barrington and
Pittsfield. This upgrade is not required within the six-year
view of the business plan due to lower penetration figures
for this portion of the network. Cost figures are provided
for future needs.
- Upgrade #3: Leased Fiber Capacity to Springfield: The
DS3 link between Pittsfield and Springfield will become
a capacity bottleneck in year 3. To alleviate the bottleneck,
a leased fiber agreement is recommended over a fiber build
scenario due to the complexity and cost of the proposed
build. Potential providers of leased dark fiber for this
portion of the network are
1. El Paso Energy – with planned
construction in Year 2000,
2. Williams – with planned construction
in Year 2000,
3. NEON – a likely developer
in the area, but no formal plans to date,
4. Bell Atlantic – has fiber,
however, may not have spare fiber in all required segments
of the route, and
5. Qwest – currently has fiber
through Pittsfield but is unable to provide fiber access
or transport services to Springfield at this time. |
With the use of ATM technology, over-subscription
is used to maximize available bandwidth enabling the network
to transport up to 10 times the actual bit rate running across
the fiber, which in this case is 155 Mb/s (an OC-3). As with
the phase 1 network, the network uses a conservative 6:1 over-subscription
ratio. The actual throughput depends on the mix of end customer
traffic and the types of services carried.
Phase 3: Enhanced Services
It is worthwhile to note that after the completion
of Phase 2 upgrades, the Berkshire Connect network is a network
with substantial assets. These assets include:
- A 48-fiber buried fiber cable route extending the length
of the county from north to south.
- An expandable OC-3 microwave network that can grow to
accommodate additional OC-3 spans.
- A long-term fiber lease agreement with a third party
fiber provider to provide an expandable and a robust egress
network.
- A core ATM switch network capable of offering traditional
as well as packet and cell based service offerings.
- Three full-function and expandable hub sites designed
specifically to address the collocation needs of end-users,
service providers, and enhanced service providers.
- Virtual and physical collocation facilities at key Bell
Atlantic central offices providing for economic interconnection
with Bell Atlantic.
- A solid base of regional enterprise customers and regional
municipal and educational users.
These assets will enable Berkshire Connect
to expand and grow into many lines of service as future needs
dictate. Some options for enhanced service offerings from
Berkshire Connect include:
- High-bandwidth data services for enterprise customers
including 10 and 100 Mb/s Ethernet services and IP services.
- Video Conferencing services.
- Fiber-based private LAN services for enterprise customers.
- Lease of capacity to other service providers
- Lease of dark fiber to enterprise customers and to service
providers.
- Enhanced service offerings including fiber-based data
storage applications.
- Collocation services including space lease and technical
support services.
- Resale of Bell Atlantic services
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