This paper describes a solution to extend the Managed Bandwidth Service (MBS), which is provided on a backbone network using MPLS VPNs, to non-MPLS domains and also evaluates it. It is based on the Class Based Weighted Fair Queueing mechanism (CBWFQ) [4] and describes the way it should be implemented to provide guaranteed bandwidth connections. In particular, CBWFQ can provide assured bandwidth connections when simultaneously leads to efficient bandwidth utilization. In addition, the proposed solution is being tested on simulation environment (using the Network Simulator) in order to evaluate its performance characteristics. On the simulation tests had been reserved specific amount of bandwidth for specific flows and their throughput was measured in order to understand if the proposed solution works well. Finally, the results are very well and prove that this method can guarantee bandwidth for every flow in all network conditions (congested or uncongested). At last, the paper presents a technical example of router configuration for implementing the MBS service according to the basic proposed solution.