To store packets in switches,
a buffering strategy is needed to resolve contentions in the output ports. Optical switches
currently use optical fibers as Fiber Delay Lines (FDL) to emulate buffers by delaying
packets for a fixed time (Xu et al., 2001). The FDLs are far away behind the random access
electronic buffers, in term of cost, performance, and deployment simplicity.
All-Opt cal Intermet: Next-Generat on Network Infrastructure
Copyright ?© 2007, Idea Group Inc. Copying or distributing in print or electronic forms without written permission
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Optical Burst Switching
The concept of burst switching first emerged in the context of voice communications. OBS is
an adaptation of a stander known as ATM Block Transfer (ABT) developed by the telecommunication
standardization sector of the International Telecommunication Union (ITU-T) for
burst switching in Asynchronous Transfer Mode (ATM) networks. OBS consists of core nodes,
built from optical and electronic components, and edge (Ingress/ Egress) nodes connected
by WDM links. OBS differs from optical packet switching and the original burst-switching
concept introduced in the 1980??™s (Amstutz, 1989; Kulzer & Montgomery, 1984) in a main
aspect, that is, the separation of the control and the data payloads, both in time (i.
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