Improved Algorithm for the Packet Routing in Telecommunication Networks

Abstract

Packet routing efficiency is and will remain one of the major factors that have a major impact on a network performance and a quality of service. One of the most common routing protocols used in autonomous Internet systems is the Open Shortest Path First (OSPF) protocol. The OSPF protocol performs packet transmission using the shortest paths, calculated according to a certain, but only one criterion. Default criterion is channels bandwidth, but in general any criteria can be selected. The disadvantage here is that channels loading is not considered and thus packets are routed to a shortest but potentially overloaded path. In wider sense usage of single criteria may results in routing through paths suboptimal or even inappropriate by other criteria. The growth of the network traffic, and especially the increase of its multimedia component drives continuous improvement of routing methods in existing telecommunication networks. Network performance will benefit from more advanced routing methods, which would take into account several network characteristics, important for specific services quality. In given work a new algorithm of a gateway selection for the routing tables of autonomous Internet systems is proposed. The algorithm is based on the OSPF protocol but takes into account three criteria: channel bandwidth, the number of intermediate nodes in the path and the signal propagation delay. Weighting coefficient for each criteria is introduced. Besides that, the integral criterion is proposed based on optimal path weights for individual criteria and path weights found by two other criteria. The total relative deviation of the path weight from the path weights calculated according to individual criteria is used as the optimization criterion. The purpose of optimization is to minimize this deviation. Routing tables constructed using proposed algorithm ensure packets transmission through the optimal path, selected according to the integral criterion, taking into account the three criteria and their coefficients of importance. Further research may be conducted to expand the list of criteria used in the optimization process.

Minimizing the Number of Distrustful Nodes on the Path of IP Packet Transmission

“…Sometimes it is important to take into account not only the values of the metrics of various criteria, but also the ratio between them. For example, in studies [5,9], the indicators of three criteria (throughput, hops, and delay) and their weight are taken into account. This task differs from the previous ones, considering one criterion, but, at the same time, an additional condition will be formulated.…”

“…These are works of a system-wide nature, which analyze, for example, static and dynamic routing 2 of 16 or centralized and decentralized routing [2,3], as well as works that analyze, compare, and improve specific protocols under certain conditions. In particular, many works are devoted to the implementation of the widely used OSPF protocol in Wide Area Networks (WANs) [4][5][6][7][8][9]. Different tools are used for routing research, such as the Riverbed Modeler [10], the GNS3 [7], the Cisco Packet Tracer simulator [11], etc.…”

“…It involves the classification of data packets into critical and normal ones and, based on this categorization, offers two delivery paths instead of one, as is usually the case. The case in which three criteria are considered is presented in other studies [5,9].…”