Service differentiation scheme in OBS networks

Abstract

In order to achieve service differentiation, especially loss differentiation, in optical burst switching (OBS) networks, we propose a dynamic fiber delay line (FDL) partitioning algorithm, which divides FDLs into several groups over a feed-forward output buffering architecture. In the proposed scheme, a plurality of traffic classes and FDL groups can be considered, and each FDL group is assigned to traffic classes, so that the target loss probabilities of classes are guaranteed. Also, the optimal number of FDLs for each FDL group by the proposed algorithm is decided in Poisson traffic environments. The extensive simulation results validate the effectiveness of the proposed dynamic FDL partitioning algorithm for the loss differentiation in OBS networks.

Service differentiation using shared fiber delay line bank in OBS networks

“…The first issue is the distribution of the lengths of the delay lines and the other is the data burst forwarding policy [15]. FDL banks can be configured as either degenerated configuration or non-degenerated configuration.…”

“…− A data burst will be discarded when the FDL bank is full, as shown in [15] − It will be dropped even though it can be successfully scheduled on a certain output port because a delay line may be occupied by data bursts headed for other output ports.…”

“…In addition, one of the most important issues that must be dealt with is the need for service differentiation schemes for various applications. In order to guarantee QoS, various mechanisms have been proposed for OBS networks [4,[8][9][10][11][12][13][14][15].…”

“…In [15], to accomplish QoS requirements, a dedicated FDL bank architecture was considered and an algorithm was also proposed. All FDLs in each bank are divided dynamically depending on QoS requirements of each traffic class.…”

“…5 draws the conclusion of this article. Figure 1 shows the feed-forward type dedicated FDL bank architecture used to achieve service differentiation [15].…”