QoS guaranteed recovery schemes by introducing multiple classes in IP over WDM networks

Abstract

In this paper we propose a novel recovery scheme to guarantee QoS (quality of service) and reduce spare capacity for restoration by introducing multiple classes based on $MP\lambdaS$ (MultiProtocol Lambda Switching) control plane in IP over WDM networks. We propose two novel recovery schemes for targeting: 1) QoS guaranteeing by focusing more on recovery time (Hybrid recovery scheme with multiple classes), and 2) saving spare resources for restoration and differentiating restoration time among diverse services (Shared recovery scheme with multiple classes). In these schemes, we assign one of three classes on a label request message for establishing backup path according to the diverse protection demands and apply dedicated or shared recovery strategies for each class. The proposed schemes are compared with the 1+1 dedicated protection scheme and the SRLG (shared risk link group) applied recovery scheme in terms of the required number of wavelengths for satisfying OLSP (optical label switched paths) setup requests, blocking rate, and restoration time. The proposed recovery schemes satisfy the required QoS/CoS guarantee in restoration time and reduction in spare capacity for backup paths, and thus show better performance than the existing schemes through the modified $MP\lambdaS$ signaling messages.