On the Cost of Using MPLS for Interdomain Traffic

Multi-Protocol Label Switching (MPLS) is currently heavily used inside autonomous systems for traffic engineering and VPN purposes. We study the cost of using MPLS to carry interdomain traffic by analyzing two one day traces from two different ISPs. Our study shows that a hybrid MPLS+IP solution can significantly reduce the number of LSPs and signalling operations by using MPLS for high bandwidth flows and pure IP for low bandwidth flows. However, the burstiness of the interdomain LSPs could be a problem.