A Comprehensive Evaluation of the Impact of ATM QoS Mechanisms on Network Performance for Multimedia and Data Applications

The Asynchronous Transfer Mode (ATM) network is crucial due to its ability to efficiently transmit data, provide reliable connections, and support various service classes with specific Quality of Service (QoS) requirements. In this paper, we utilize the OPNET network simulation software to model an ATM network and analyze the impact of QoS classification on network performance. We investigate the effects of Constant Bit Rate (CBR), Variable Bit Rate (VBR), Available Bit Rate (ABR) and Unspecified Bit Rate (UBR) models on various network traffic types such as voice, video and data. For voice traffic, we examine key QoS parameters including Jitter, Packet Delay Variation and End-to-End Delay. For video traffic, we evaluate Packet Delay Variation and End-to-End Delay. Additionally, we analyze Download Response Time for data traffic to assess the influence of QoS on the ATM network. Our results demonstrate that CBR and VBR are preferred for real-time traffic like voice and video, providing low delay and jitter. The simulation approach enables us to test various configurations and gain insights not possible in hardware tests. Our findings can help network operators determine the optimal QoS settings and tradeoffs when deploying ATM for modern multi-service networks.