Providing absolute differentiated services for optical burst switching networks: loss differentiation

The provision of absolute differentiated services for optical burst switching (OBS) networks based on dynamic wavelength assignment is investigated. Unlike existing quality of service (QoS) schemes, such as buffer-based and offset-time based ones, the proposed dynamic virtual lambda partitioning (DVLP) scheme does not mandate any buffer or extra offset time, but can achieve absolute service differentiation between classes. This new DVLP scheme shares wavelength resources based on several different class priorities in an efficient and QoS guaranteed manner. Furthermore, DVLP is robust: this means that each traffic class, with a loss probability conforming to the target value, continues to receive the required QoS, despite the presence of misbehaving packets, such as bursty arrival traffic. The conditions in which the DVLP scheme is feasible are stated, and the performance results are given for the proposed scheme, which effectively guarantees the target loss probability of each traffic class, both in Poisson and self-similar traffic environments.