QoS Issues Evaluation in MPLS Networks Gagan Deep 1 Ashwani Kush 2 Brijesh Kumar 3 Department of Comp Science, University College, Kurukshetra University India 1,2 Lingaya’s Institute of Management & Technology, Faridabad, Haryana 3 rozygag@yahoo.com 1 , akush20@yahoo.co.in 2 , brijesh10@hotmail.com 3 ABSTRACT Mobile Internet connectivity is the fastest growing business in the telecommunications market because of the evolution of digital cellular, portable computing and personal communication technologies. It is playing a vital role in shaping the 21st century communications paradigms. So service demands in wireless communications have significantly changed. The traditional focus was commonly limited to voice channels over wireless point-to-point connections between the base station and the wireless terminal/phone, thus not requiring any complex routing or switching networking topologies. With the introduction of mobile data services, the emphasis shifts from sheer coverage to the flexibility and functionality of the network. A large number of the current wireless service applications require broadband data communications as well as advanced wireless networking services. These advanced services require a new generation network architecture that is powerful and yet flexible enough to enable fast change. This paper introduces the concept of MPLS, its basic features and applications with performance evaluation details. 1.0 INTRODUCTION The first available solutions performing data transfer over the GSM network include the Short Message Service (SMS), that allows a basic e-mail exchange, and the traditional low-speed Circuit Switched Data (CSD), that may be used to access Internet services. The main drawbacks of CSD are that they have very limited bandwidth capacity (9.6 kbps or 14.4 kbps depending on the employed coding scheme) and the sub-optimal use of the radio interface. 1.1 BASICS OF MPLS (MULTI PROTOCOL LABEL SWITCHING) Over the last few years, the Internet has evolved into a ubiquitous network and inspired the development of a variety of new applications in business and consumer markets. These new applications have driven the demand for increased and guaranteed bandwidth requirements in the backbone of the network. In addition to the traditional data services currently provided over the Internet, new voice and multimedia services are being developed and deployed. In addition to the issue of resource constraints, another challenge relates to the transport of bits and bytes over the backbone to provide differentiated classes of service to users. The exponential growth in the number of users and the volume of traffic adds another dimension to this problem. From a QoS standpoint, ISPs will better be able to manage different kinds of data streams based on priority and service plan. MPLS provides a robust QoS control feature in the Internet. In addition, MPLS class of service feature can work in conjunction with other QoS architectures for IP networks defined by the Indian Engineering Task Force (IETF). Integrated Services [1] using Resource ReSerVation Protocol [2] and Differentiated Services [3] are the two models defined by the IETF for providing QoS in IP networks. Combining MPLS with DiffServ is particularly popular, and provides the required levels of end-to-end QoS management in a scalable way. MPLS support for DiffServ has been explained in [4]. In fact, both MPLS and DiffServ are the real enhancements to IP networks. As they don't make any requirements about each other, so they can work independently. Summarizing MPLS, it will play an important role in the routing, switching, and forwarding of packets through the next-generation network in order to meet the service demands of the network users. So, Multi Protocol Label Switching is a versatile solution to address the problems, faced by present-day networks as speed, scalability, quality-of-service management, and traffic Engineering [5]. The requirements for traffic engineering over MPLS have been proposed in [6]. MPLS has emerged as an elegant solution to meet the bandwidth-management and service requirements for next-generation Internet protocol based backbone networks. MPLS addresses issues related to scalability and routing and can exist over existing asynchronous transfer mode and frame-relay[7] networks. LIOA(least interference optimization algorithm) introduced by [8] which performs better than several well known routing algorithms. LIOA calculates a cost for each link based on the number of connections through the link and the remaining capacity and then it find a shortest path. [9]presents an optimal centralized algorithm (Constrained Bellman-Ford) to find the least cost delay-constrained path. The algorithm performs a breadth first search to find the optimal path. [10] suggests the MIRA(Minimum Interference Routing Algorithm). The objective is to route the flow request over a path which minimizes the interference with possible future requests.