Performance Evaluation of Fiber Delay Line Buffer with Partially-Shared Part

In this paper, a partially-shared FDL(Fiber Delay Line) buffer is presented in an optical packet switch to reduce the device cost. This FDL buffer has individual FDL and shared parts. When the arrival packet number is low, it works only with an individual part. On the other hand, when the number is high, the FDL buffer occupies the shared part, and it can deal with more packets simultaneously than in the case of an individual part only. By using the shared FDL part, total number of switch elements decreases and we obtain a higher TCP throughput than with an FDL buffer at the same scale having no shared part. Moreover, multi-stage partially-shared FDL can allocate shared part according to loads on each output link. Improved performances are shown through computer simulations.