Journal of Information Processing Systems, Vol.7, No.2, June 2011 DOI : 10.3745/JIPS.2011.7.2.241 241 CASPER: Congestion Aware Selection of Path with Efficient Routing in Multimedia Networks Mohammad S. Obaidat*, Sanjay K. Dhurandher** and Khushboo Diwakar** Abstract—In earlier days, most of the data carried on communication networks was textual data requiring limited bandwidth. With the rise of multimedia and network technologies, the bandwidth requirements of data have increased considerably. If a network link at any time is not able to meet the minimum bandwidth requirement of data, data transmission at that path becomes difficult, which leads to network congestion. This causes delay in data transmission and might also lead to packet drops in the network. The retransmission of these lost packets would aggravate the situation and jam the network. In this paper, we aim at providing a solution to the problem of network congestion in mobile ad hoc networks [1, 2] by designing a protocol that performs routing intelligently and minimizes the delay in data transmission. Our Objective is to move the traffic away from the shortest path obtained by a suitable shortest path calculation algorithm to a less congested path so as to minimize the number of packet drops during data transmission and to avoid unnecessary delay. For this we have proposed a protocol named as Congestion Aware Selection Of Path With Efficient Routing (CASPER). Here, a router runs the shortest path algorithm after pruning those links that violate a given set of constraints. The proposed protocol has been compared with two link state protocols namely, OSPF [3, 4] and OLSR [5, 6, 7, 8].The results achieved show that our protocol performs better in terms of network throughput and transmission delay in case of bulky data transmission. Keywords—Routing, Multimedia Networks, Congestion-aware Selection, MANET, CASPER, Performance Evaluation 1. INTRODUCTION Mobile Ad Hoc Networks (MANETs) [1,2] have the property of unstable link connectivity between nodes that keeps on breaking and then reforming due to the mobility of the nodes. As the links are highly unstable, the link bandwidth too keeps on changing. Due to this feature of MANETs, transmission of bulky data with high bandwidth requirements might become a prob- lem. The protocol proposed in this work aims at eradicating this problem. This protocol is a link state protocol that maintains the link state of all the nodes in the network. 1.1 Motivation and Contributions The use of a congestion reduction technique is important while transmitting bulky data in Manuscript received April 13, 2011; accepted May 15, 2011. Corresponding Author: Mohammad S. Obaidat * Department of CS & SE, Monmouth University, NJ, USA (obaidat@monmouth.edu) ** CAITFS, Division of Information Technology, Netaji Subhas Institute of Technology, University of Delhi, New Delhi, India (dhurandher@rediffmail.com, diwakar_khushboo@yahoo.co.in) Copyright ⓒ 2011 KIPS (ISSN 1976-913X) Invited Paper