Reservations inside clusters of all-optical core nodes achieve distributed burst aggregation and switching improving efficiency and loss

Clustering neighbouring nodes of an all-optical core network into medium-sized rings controlled by a master node allows two-way reservation-based control to aggregate bursts destined for other clusters in a lossless way with tolerable delay. The densely packed bursts can then be sent over static or switched light paths and be received in the destination cluster ring without the delay of end-to-end reservations. This hybrid approach where two-way reservations are geographically limited inside clusters only avoids both the handicap of heavy loss of one-way Optical Burst Switching (OBS) and the intolerable delay and multiplexing gain of end-to-end reservations. In addition, the number of multi-port space-switching all-optical nodes is reduced delegating part of this function to the distributed control of the laser sources of the ring under the guidance of the medium access protocol. Copyright # 2007 John Wiley & Sons, Ltd.