Towards Coordinated Interdomain Traffic Engineering

We argue that today’s ad hoc inter-domain traffic engineering techniques be replaced with an architecture that is based on explicit coordination between ISPs. With explicit coordination, ISPs exchange information about their traffic and routing options, and all ISPs impacted by a potential routing change negotiate the actual change. This increases efficiency because it allows ISPs to find “win-win” routing outcomes that benefit both relative to routing without coordination; one ISP need not guess the policies of others to successfully engineer its own network. It also offers greater stability because it makes resource policy conflicts visible before routing changes uncover them, allowing them to be resolved and avoiding inadvertent violations. We sketch the building blocks of such an architecture, and use simulation to show it has the potential to yield significant cost benefits.