Fiber Delay Line-Random Early Detection QoS Scheme for Optical Burst Switching Networks

Abstract

Optical Burst Switching (OBS), a novel paradigm, combines the benefits of Optical Packet Switching and Optical Circuit Switching technologies, thus providing a better integration of the optical layer and traditional IP/ATM layer, through the smooth transition via the OBS core and edge nodes. Fiber Delay Line-Random Early Detection (FDL-RED) is a new QoS scheme which can be implemented in OBS core nodes to achieve service differentiation among classes. Classes of traffic are isolated by assigning Fiber Delay Lines (FDL), which function as optical buffers, based on the Random Early Detection (RED) technique. This is a distributed scheme such that service differentiation at individual core nodes can be uniquely determined by a set of probability functions. Thus, each node can utilize the scheme to implement QoS according to its own policies as well as to overcome problems introduced by Offset-Time based QoS schemes, which arise because service differentiation is defined at the edge node and cannot be changed along its path.