PCE QoS tools and related scalability in WDM networks

The virtual circuit characteristic of MPLS and GMPLS architectures has enabled the implement of Traffic Engineering (TE) and Differentiated Services (Diff-Serv) profile to networks. Both schemes are possible by the application of preemption policies and priority of path assignment. With the advent of Path Computation Element (PCE) the routing task can be centralized and properly (re-)designed to accommodate MPLS´ and GMPLS´ Diff-Serv and TE characteristics. However, as a centralized system, the complex characteristics of heterogeneous networks and the extra data involved on TE and Diff-Serv constrains and requirements for path computations may overload the PCEs´ processing capacity and radically increase the number of PCEP control messages exchanged, jeopardizing the scalability of the system in general. In this article we present an analysis on the current standardized PCE tools in a WDM network in terms of the number of control messages exchanged impact on the system and its optimization performance.