The Unpredictable Certainty White Papers (1997) / Chapter Skim
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Toward a National Data Network: Architectural Issues and the Role of Government
Toward a National Data Network: Architectural Issues and the Role of Government
Pages 217-227
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From page 217... ...
These concepts are best discussed in terms of contrasts: · Voice versus data communications, · Circuit versus packet switching, and · Shared versus dedicated networks. In a simple sense, data communications are between computers, and voice communications are between people.
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From page 218... ...
There was no public packet switched data network nor was there a large demand for one. Private data networks grew alongside the private voice networks, with packet switches on customer premises and private lines connecting the switches.
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From page 219... ...
STUDY METHODOLOGY Three physical network models were formulated and evaluated for cost-effectiveness over a range of traffic levels. These models were cladded to represent the generic data communications requirements of a single federal agency, the federal government as a whole, and the general public as a user of the Nit.
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From page 220... ...
The final level in the hierarchy consists of routers in the LEC wire centers serving actual users. Access to these routers occurs over the customer's local loop and can take venous forms: Dedicated local loop connect directly to data tenrunating equipment, .
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From page 221... ...
. A single, scalable traffic model was used to evaluate all three physical network models (agency model, government model, ND model)
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From page 222... ...
March 1994 NSF Backbone All FTS2000 Agencies DOD Operational Networks NII 0.0075 0.1-0.4 0.6 1.4-5.6 ~6.0 >20.0 The current FTS2000 packet switched service (PSS) carries only a small percentage of the civilian agency data communications traffic, most of the traffic is carried over private networks using circuits procured under FTS2000 dedicated transmission service (DTS)
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From page 223... ...
Network management costs were estimated at 25 percent of the equipment and transmission costs, based on current experience wig agency networks. Implementing management cost estimates as a percentage assumes that network management will show the same economy-of-scale effects as Me other cost elements.
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From page 224... ...
The unit costs predicted by the mode} at the lowest traffic levels are consistent with the current unit costs for FTS2000 packet switched service, which is operating at these traffic levels. It can readily be seen that large single agencies can achieve economies with private networks at Weir current volumes of 0.
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From page 225... ...
FIGURE 6a Monthly cost government model.
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From page 226... ...
- ~ Govemment -~-Multiple Networks 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 TeraByteslDay FIGURE 7a Monthly cost NII model. FIGURE 7b Unit cost NII model.
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From page 227... ...
The infrastructure costs of a National Data Network show a marked economy-of-scale effect at He volumes represented by the federal government data communications traffic.
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