On the stability and diversity of Internet routes in the MPLS era Abstract   Stability and diversity of endtoend routes are key properties of Internet that have a large effect on the design of networks and networked systems. As the Internet evolves and deploys new technologies, it is important to reassess these properties in the face of the new realities. This paper evaluates the stability and diversity of Internet routes with emphasis on the impact of the widely deployed MultiProtocol Label Switching (MPLS). In particular, we analyze two datasets: (1) high frequency (once per minute) traceroutes originating from a number of PlanetLab hosts to a set of destinations distributed around the Internet (random hosts extracted from the Alexa list of top1M websites), and (2) traceroutes originating from a large number of Ripe Atlas probes to a number of hosts (mostly root DNS servers). We find that Internet routes are significantly less stable than previously reported, at least according to one common metric (the route persistence), and much more diverse. At the same time, these more frequent route changes do not translate to high variability of routetrip time (RTT) delays between hosts, as RTTs tend to stay similar across route changes. Notably, with regard to diversity, we show that higher diversity is likely due not to a real change in the Internet but rather to underestimation by previous studies. Finally, our assessment of MPLS role in increased path instability produced inconclusive results as MPLS appears to be a significant contributor in the Ripe Atlas data set but not in the Plant Lab dataset.

A Combined BGP and IPMPLS Resilient Transit Backbone Design The Internet is a collection of interconnected Autonomous Systems (ASes) that use the Border Gateway Protocol (BGP) to exchange reachability information. The design of an optimal BGP overlay for an AS is a known NPHard problem this team tackled previously for IP networks, i.e, for the best effort paradigm. However, most Internet providers implement their backbones by combining IP routing with MPLS (Multipro tocol Label Switching) for QoSaware traffic forwarding. MPLS forwarding incorporates traffic engineering and more efficient failover mechanisms. The present work introduces a coordinated design of both IPMPLS substrates. Our contribution is on proposing an optimal and yet resilient topology design for an IPMPLS Internet backbone, which takes advantage of traffic engineering features to optimize the demands, maintaining the aforementioned iBGP overlay optimality.