Optimization algorithms for proxy server placement in content distribution networks

Popular Web sites receive an enormous share of Internet traffic. These sites have a competitive motivation to offer better service to their clients at lower cost. One of the solutions is to using content distribution network (CDN). When we design a CDN we need to find proxy server placement to provide its clients with the best available performance while consuming as little resource as possible. This is an optimization problem. Among the solutions greedy algorithm yields better result with low computational cost. The drawback is that it is easy to trap in the local optimum. We propose genetic algorithm to solve this problem. We mathematically model the optimization problem and then give details about how to apply genetic algorithm to proxy server placement problem. Simulation results for a simple topology are presented for both greedy algorithm and genetic algorithm.