Optical burst switching(2)

The purpose of optical burst switching (OBS) is to dynamically provision sub-wavelength granularity by optimally combining electronics and optics. OBS considers sets of packets with similar properties called bursts. Therefore, OBS granularity is finer than optical circuit switching (OCS). OBS provides more bandwidth flexibility than wavelength routing but requires faster switching and control technology. OBS can be used for realizing dynamic end-to-end all optical communications.

In OBS, packets are aggregated into data bursts at the edge of the network. Various assembling schemes based on time and/or size exist (see burst switching). OBS features the separation between the control plane and the data plane. A control signal (also termed burst header or control packet) is associated to each data burst. The control signal is transmitted in optical form in a separated wavelength termed the control channel, but signaled out of band and processed electronically at each OBS router, whereas the data burst is transmitted in all optical form from one end to the other end of the network. The data burst can cut through intermediate nodes, and data buffers such as fiber felay lines may be used. In OBS data is transmitted with full transparency to the intermediate nodes in the network. After the burst has passed a router, the router can accept new reservation requests.

September 22, 2011

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