Advanced Internet Protocols, Services, and Applications

12

IP TRAFFIC ENGINEERING

Implementing the most appropriate set of routes can increase the network resource utilization rate and network throughput of Internet Protocol (IP) networks. Since it optimizes the assignment of traffic resources, additional traffic can be supported. It also suppresses network congestion and increases robustness in the face of traffic demand fluctuations, most of which are difficult to predict. One useful approach to enhancing routing performance is to minimize the maximum link utilization rate, also called the network congestion ratio, of all network links. Minimizing the network congestion ratio leads to an increase in admissible traffic. This chapter describes several routing schemes to maximize network utilization for various traffic-demand models, where the Multiprotocol Label Switching (MPLS) and Open Shortest Path First (OSPF) technologies are considered.

12.1 MODELS OF TRAFFIC DEMANDS

When the routes between source and destination nodes are designed to utilize network resources, traffic demands for each source and destination pair need to be predicted. This section introduces three traffic-demand models: a pipe model, a hose model, and an intermediate model.

The traffic demand d_pq between source node p and destination node q is denoted as d_pq. The traffic matrix is expressed by T = {d_pq}, whose dimension is N × N, where N is the number of nodes in the network. If each element of the traffic matrix d_pq is specified, the traffic model is called the ...