Abstract: Packet networks are currently enabling the integration of heterogeneous traffic with a wide range of characteristics that extend from video traffic with stringent QoS requirements to best-effort traffic requiring no guarantees. QoS guarantees can be provided in packet networks by the use of proper packet scheduling algorithms. Similar to the trends of computer revolution, many scheduling algorithms have been proposed to meet this goal. The First-Come-First-Served (FCFS), which is mostly used in conventional networks, has been widely adopted for best-effort traffic. In addition, many scheduling algorithms have also been proposed to provide different schemes of QoS guarantees. Among which include the Earliest Deadline First (EDF) and the Differentiated-EDF (Diff-EDF). In this study, we propose a new priority assignment scheduling algorithm, Hierarchical Diff-EDF, which can meet the real-time needs while continuing to provide best effort service over heterogeneous real-time network traffic. The Hierarchical Diff-EDF service meets the flow miss rate requirements through the combination of single step hierarchal scheduling for the different network flows (video, audio and text) and the admission control mechanism that detects the overload conditions to modify packets` priorities. The implementation of this scheduler is based on the multi-agent simulation that takes the inspiration from object-oriented programming. The implementation itself is aimed to the construction of a set of elements which, when fully elaborated, define an agent system specification. When evaluating our proposed scheduler, it was extremely obvious that the Hierarchical Diff-EDF scheduler performs much better than both EDF and Diff-EDF schedulers.