الفهرس 
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Abstract
The problem ot computer network design is investigated in A linear zero-one programming model is developed the optimal design of distributed long-haul point-to-point Compared with the previous work in this area, complete, since it considers simultaneously followinS issues in designing computer networks;
System reliability
Distribution of computing power
of programs and databases
Assignment of channels allocation and their capacities. Return flow of information
Routing strategy
The objective of the design process is the achievement of design requirements et the miniumum cost. The following considered by the model:
Computers equipments cost software cost
installation cost which includes:
Fixed cost depending on the channel capacity Variable cost depending on the channel length Datebases storage cost
Programs storage cost
6) usage cost of channels which includes:
a- Cost of queries and updates from users to programs (including the return flow of information)
b- Cost of queries and updates tram programs to databases (including the return flow of information)
Several design problems had been overconed:
1) No restriction is imposn on the topology of the designed network, and the network connectivity is optimally determined depending upon the nodes failure probability and the requirement of the reliability measure.
2) Depending on the node failure probability and the
rerquirement of database availability measure, multiple copies of the same database are allocated at different sites in the network, and independent routes are assigned to access information at these copies.
3)The problem of dependencies between programs and databases
is taken into account, thus, in order to access a database, the transaction has to be processed by a particular program
related to that database.
4)The problem of return f~ow of information, as the response of a query transaction or the acknowledgment of an update transaction, is also considered by the model.