Abstract
Abstract.Multiprotocol Label Switching (MPLS) has emerged as a key technol-ogy for providing quality of service (QoS) guarantees in IP networks. This paper presents an extensive simulation-based evaluation of MPLS QoS mechanisms. Specifically, different queuing policies -First In First Out (FIFO), Priority Queu-ing (PQ), and Weighted Fair Queuing (WFQ) are implemented and analyzed for providing end-to-end QoS for real-time voice and data applications over an MPLS VPN backbone. The network simulations are performed using the OPNET tool with detailed MPLS, VPN, and queuing parameters configuration. Perfor-mance is evaluated across multiple metrics including jitter, delay variation, end-to-end delay, traffic sent/received for both voice and data flows. The results demonstrate that FIFO queuing delivers the best QoS performance for voice traf-fic, providing simple first-in, first-out buffering. WFQ is shown to outperform PQ for voice flows. All queuing mechanisms can meet QoS requirements for voice and data applications. The paper provides a comprehensive investigation into configuring MPLS networks with QoS capabilities. Key findings show that MPLS VPNs effectively reduce networkcomplexity and costs. FIFO emerges as an optimal queuing technique for enabling QoS services in MPLS networks car-rying multimedia applications.