Optical slot size dimensioning in IP/MPLS over OPS networks

Current optical technology allows an easy implementation of synchronous, time-slotted optical networks. In contrast, traffic in electrical domain (for instance IP) mainly consists of asynchronous, variable length packets. Therefore a packet format adaptation process is needed between electrical and optical domains, the optical slot size being in this process a crucial parameter, which strongly influences the bandwidth utilisation and determines the overall network performance. In this paper we address the problem of designing this adaptation layer and of dimensioning the optical slot size in IP/MPLS over optical packet switched networks. Three different optical packet formats, namely fixed-length packet, slotted variable-length packet, and fixed-length packet with traffic aggregation are discussed. To find the optimum size, the efficiency of such formats are evaluated by simulations.