Method for efficient distributed data communications network access network configuration

A computer system for constructing a data communication network having a number of terminals comprising:

• i. backbone nodes for routing data traffic within the backbone;
• ii. concentrators connected between said terminals and said backbone nodes;
• and
• iii. a plurality of links for connecting said terminals with said concentrators;
• said computer system having:
• a. means for identifying a site for a median concentrator from among a plurality of candidate concentrator sites, said candidate concentrator sites comprising a mandatory concentrator site and an optional concentrator site, which median concentrator is located at that candidate concentrator site to which all of said terminals can be connected by said links at the lowest cost and adding said concentrator to the network;
• b. means for adding a mandatory concentrator to the network, said mandatory concentrator being a concentrator located at said mandatory concentrator site, and assigning said terminals to said mandatory concentrator so as to minimize the cost of the network;
• c. means for evaluating the effect on the network of adding an optional concentrator at each of said optional concentrator sites to the network, adding that optional concentrator that most reduces the cost of the network, and reassigning terminals to said added optional concentrator so as to minimize the cost of the network;
• and
• d. means for evaluating the effect on the network of removing optional concentrators from the network, removing that optional concentrator whose removal reduces the cost of the network, and reassigning those terminals previously assigned to the that optional concentrator removed from the network to remaining concentrators so as to minimize the cost of the network.