Increasing the network performance using multiple tables based QoS routing with load balance

With the increasing diversity of network applications, it has become crucial for the Internet to offer various services. In the Internet a simple shortest path routing algorithm is employed, however, it may not be adequate in networks that provide Quality of Service (QoS) guarantees to applications such as real time applications. Since the goal of the QoS routing is to find a path that satisfies the given requirements and may increase the global network resource utilization, an advanced QoS-aware routing technology in the current IP networks is needed to realize next generation ubiquitous networks. In this paper, we propose a distributed link state QoS routing with multiple routing tables obtained upon different link costs to effectively accommodate multi-class traffic such as real time QoS traffic and best-effort traffic. Selecting a path for QoS traffic can have an effect on overall the network. Therefore, how much QoS traffic has to be routed on the shortest path will have an impact on the behavior of Best Effort Traffic. For that we used a dynamic threshold based on network state to split QoS traffic between alternatives path. The significance of the proposed scheme lies in reducing the packet loss probability of the QoS traffic. This scheme can prevent the QoS traffic from concentrating on some links and allow at the same time to improve the best-effort traffic throughput. We investigate the characteristics of the proposed multi-class routing schemes by computer simulations. We have found that both packet loss of QoS traffic and the throughput of Best-Effort can be improved by using the proposed scheme.