Bridging the gap for end-to-end QoS in the optical Internet

QoS guarantees need to be constant along the entire path between source and destination, i.e. end-to-end. However, for traffics across several domains, the domains are often with different administrations and technical characteristics. To guarantee QoS in the inter-domains is becoming a challenge for end-to-end QoS. Especially, for DiffServ flows traversing a transit WDM network in the Optical Internet, there exits a QoS gap between the DiffServ-aware MPLS sub-network and the MPlambdaS sub-network. In this article, we study the convergence of the QoS schemes in these two sub-networks to achieve end-to-end QoS in the Optical Internet. We first give a review of QoS models in the IP network and WDM optical network and compare their difference for supporting QoS. Then, we study the end-to-end QoS mechanism in the Optical Internet, and propose a QoS mapping method between the IP/MPLS sub-network and the MPlambdaS sub-network. Based on the QoS mapping method, an end-to-end QoS guaranteed LSP provisioning scheme in the Optical Internet is presented at this end of the paper.