As an alternative solution to provide the quality of services (QoS) for broadband access over Ethernet Passive Optical Network (EPON), we present the usage of MAC control message for plural class queues and a traffic-class burst-polling based delta dynamic bandwidth allocation (DBA), referred to as TCBP-DDBA, scheme. For better QoS support, the TCBP-DDBA minimizes packet delays and delay variations for expedited forwarding packet and maximizes throughput for assured forwarding and best effort packets. The network resources are efficiently utilized and adaptively allocated to the three traffic classes for the given unbalanced traffic conditions by guaranteeing the requested QoS. Simulation results using OPNET show that the TCBP-DDBA scheme performs well in comparison to the conventional unit-based allocation scheme over the measurement parameters such as: packet delay, packet delay variation, and channel utilization.

In this paper, we present a priority scheduling algorithm at ATM switches with multi-class output buffers in which the service rate of each class buffer is dynamically adjusted. The service rate is computed periodically by a control scheme. We derive the design formulas of the control scheme to ensure that each class buffer occupancy converges to its desired operating point related to QoS requirement. Moreover, through dynamic service rate control in the proposed scheduling algorithm, the available channel capacity can be estimated exactly. It may be used for rate control of ABR traffic and call admission control of the other real-time traffic (CBR, VBR, etc. ).

This letter proposes a congestion control scheme for the ABR service of ATM networks which have non-responding connections. The control scheme is robust with respect to both the round trip delay and the loss of control information caused by non-responding connections. Thus, it is shown that the proposed control scheme guarantees the QoS of the network.