Influence of Label Stack Depth on the Performance of MPLS Networks

Multi-Protocol Label Switching (MPLS) is a connection-oriented paradigm suitable for metro-core networks wherein forwarding decisions in each node are based solely on a short label, much smaller than other packet headers (e.g. IP header). In order to scale and allow for hierarchical traffic aggregation, a Label stacking mechanism has been defined within Multi-Protocol Label Switching (MPLS) protocol. In this paper, label stacking is optimized for static MPLS networks and its impact on the packet processing performance is quantified in real network scenarios. Optimization is carried out by using an integer linear programming formulation and a polynomial time algorithm. Results indicate that the use of label stacking mechanism is recommended in some network scenarios. Moreover, the results evidence that a small size of label stack depth is sufficient to guarantee the performance improvement.