This paper presents fundamental aspects of MPLS over ATM method, IP over ATM method and Multimedia application traffics with different quality of service (QoS) requirements. Using a Simulation tool, the MPLS over ATM method providing ABR, CBR and VBR QoS Support, and the IP over ATM method providing a primitive UBR QoS Support for transferring data, voice and video traffics are modeled. Having simulated the models under varying offered loads, obtained Simulation results are presented. Comparing the average end-to-end delay and delay variation graphs, not only does the MPLS over ATM method provide improved results for all of the Multimedia traffics but also overcomes the worst disadvantage of the IP over ATM method producing similar and erratic results for the data, voice and video application traffics. (C) 2007 Elsevier B.V. All rights reserved.