A Simulation Study on the Performance of Integrated Switching Strategy for Traffic Management in ATM Networks Y. Ahmet S ¸ ekercio˘ glu School of Information Technology, Swinburne University ofTechnology, Melbourne, Australia ASekerci@swin.edu.au Andreas Pitsillides Department of Computer Science, University of Cyprus, Nicosia, Cyprus cspitsil@turing.cs.ucy.ac.cy Petros Ioannou Department of Electrical Engineering, University of Southern California, California, USA ioannou@bode.usc.edu Abstract Designing effective congestion control strategies for broadband networks is known to be difficult because of the variety of dynamic parameters involved such as link speeds, burstiness of the traffic, and the distances between traffic sources and switching nodes. We propose a traffic management scheme, which is in- sensitive to the propagation delay between the sources and switching nodes. We achieve this by combining Connec- tion Admission Control with a bandwidth allocation strat- egy [4,5]. By seeking the cooperation of the Available Bit Rate (ABR) sources (to limit their Peak Cell Rate, PCR) at the time of admission of a Variable Bit Rate (VBR) source to the network, the scheme eliminates the continuous con- gestion control. Our simulations show that the strategy is able to elimi- nate the ABR cell losses, achieves effective server and buffer utilization, and provides bounded delays to the VBR traffic (unlike the case without any controls). Keywords: ATM, congestion control, admission control 1 Introduction Traffic control and resource management in Asyn- chronous Transfer Mode (ATM) networks are crucial in or- der to guarantee the desired grade of service. ATM based A detailed analysis of the Integrated Switching Strategy is docu- mented in [4, 5]. networks are expected to support multimedia and multiser- vice traffic with different bit rates and quality of service re- quirements which makes design of these controls very dif- ficult. Several mechanisms will exist to control such a di- verse mixture of traffic, such as connection admission con- trol, input rate regulation, bandwidth allocation, routing, queue scheduling, and buffer management. Whilst it was recognized early that dynamic integrated control solutions are important [6], not many published works offer dynamic integrated control solutions. In [4, 5] we proposed an Integrated Switching Strategy (ISS) combining Connection Admission Control and Dy- namic Bandwidth Allocation. 2 Integrated Switching Strategy Derivation and stability analysis of the Integrated Switching Strategy (ISS) is documented in [4, 5]. There, we base the derivation of the ISS strategy on a fluid flow state model derived by matching its equilibrium state with that of an M/M/1 queuing theory model. The justification for using this model is given in [5]. By using analysis and control system type simulation we showed that a guaran- teed effective ISS strategy can be implemented, and that the behavior of the network (controlled system) can be set at prescribed levels by the setting of the three control design variables: max , max and (thus indirectly prescribing the QoS target that the network can provide). In this paper we investigate the implementation details of the ISS strategy, and evaluate its performance using an ATM cell-based simulation, implemented using OPNET [2]. It is worth pointing out that the simulation model is based on