Adaptive Dynamic Traffic Engineering for DiffServ-Enabled MPLS Networks

Abstract

The current practice in traffic engineering for Multi-Protocol Label Switching (MPLS) networks is to use expected traffic matrix and Service Level Agreements (SLA) policies as input, and compute a set of Label Switched Paths (LSPs) that satisfy the requested requirements. However, mismatch between traffic forecast and actual load including distribution among Differentiated Services (DiffServ) classes is unavoidable in dynamic network environments. This may cause overload and unbalanced utilization of LSPs. Furthermore, network failures may occur causing the failure of LSPs and possibly their planned backups; even in the case of dynamic backups, the MPLS network may not be able to establish backup paths because of resource shortages. Consequently, there is a critical need for adaptive dynamic traffic engineering. In this paper, we propose two novel schemes to realize such adaptive dynamic traffic engineering. A traffic rearrangement scheme that executes when changes on link bandwidth partitions among DiffServ classes are needed to alleviate the overload situations and a traffic restoration scheme that kicks into action whenever the MPLS network fails to restore failed LSPs upon network failures.