The study of direct virtual path layout in IP switch networks

The problem of the direct virtual path (VP) layout in IP switch network is studied in this paper. With direct VP layout, both the node forwarding cost and the transmission delay can be efficiently reduced in an TP switch network. The equivalent bandwidth method is used to represent the resource requirement of the VPs and to simplify the problem of the VP management. Two VP layout policies, the periodic layout and the dynamic layout are discussed. With respect to the periodic direct VP layout, an approximated optimal solution for forwarding cost reduction with both the maximum-weight-first (MWF) selection and the clustering selection (CS) are provided to show that the forwarding cost can be reduced dramatically. Besides the forwarding cost reduction, the periodic layout also balances the load of physical links. A heuristic algorithm with the least-loaded routing (LLR) concept is proposed for dynamic layout to adjust the usage of VPs dynamically