In this paper, we describe an algorithm for designing local-area netwo
rks (LAN's) with the objective of minimizing the average network delay
, The topology design includes issues such as determination of the num
ber of segments in the network, allocating the users to the different
segments, and determining the interconnections and routing among the s
egments. The determination of the optimal LAN topology is a very compl
icated combinatorial optimization problem, Therefore, a heuristic algo
rithm that is based on genetic ideas is used, Numerical examples are p
rovided and the quality of the designs obtained by using the algorithm
is compared with lower bounds on the average network delay that are d
eveloped.