Algorithms for IP networks design with ECMP routing enable

MENTOR (Mesh Network Topological Optimization and Routing) is an efficient heuristic design algorithm network that assigns traffic flow while selecting links to be installed. MENTOR is suitable to design networks categorized as virtual circuit packet switching such as Frame Relay, ATM and MPLS networks. However, MENTOR cannot be directly applied to datagram packet switching networks such as purely IP router network. This is because the traffic flows determined by original MENTOR are not always the shortest path routing based on IP link weight assignment. To solve this problem, Cahn proposed a modified version of MENTOR called MENTOR-II in which appropriate link weights are assigned to the installed links such that the traffic always route on the path with minimum distance. However, it should be noted that the traffic flows assigned by MENTOR-II are limited to a single path routing. This study proposed a new modified version of MENTOR called Enhance-MENTOR, or E-MENTOR, which is able to assign traffic with the Equal Cost Multi-Path (ECMP) routing. Three options of E-MENTOR are considered, i.e. E-MENTOR with single path routing only, E-MENTOR with ECMP routing only and E-MENTOR that consider ECMP routing if benefit. The three options of E-MENTOR are evaluated in term of installation cost, routing cost and reliability for 729 network design conditions. The design results are compared with those of original MENTOR and MENTOR-II.