Design and Evaluation of a Burst Assembly Unit for Optical Burst Switching on a Network Processor

Optical Burst Switching (OBS) has been proposed in the late 1990s as a novel photonic network architecture directed towards efficient transport of IP traffic. OBS aims at costefficient and dynamic provisioning of sub-wavelength granularity by optimally combining electronics and optics. In order to reduce the number of switching decisions in OBS core nodes, traffic is aggregated and assembled to bursts by the Burst Assembly Unit in an OBS ingress edge node. This Burst Assembly Unit is responsible for buffering incoming packets in queues and sending them as bursts as soon as a minimum burst length is reached and/or a timer expires. Typically, dozens of different queues must be able to handle high volumes of traffic. This paper presents the design and implementation of a Burst Assembly Unit for a Network Processor. In an evaluation of the realized implementation we point out the ability to handle traffic at line speed while having fine grained timers for all queues.