What is SDX?

Software Defined IXP (SDX) tries to bring the merits of Software Defined Networking (SDN) to interdomain routing. BGP constrains how networks can deliver traffic over the Internet. Today’s networks can only forward traffic based on the destination IP prefixes, by selecting among the routes offered by their immediate neighbors. SDN can offer direct control over packet-processing rules that match on multiple header fields and perform a variety of actions. IXPs are a compelling place to deploy these changes, given their role in interconnecting many networks and their growing importance in bringing popular content closer to end users.

SDX does more than simply replace an IXP’s switches with their OpenFlow counterparts. SDX's capabilities enable new applications, such as application-specific peering---where two networks peer only for (say) streaming video traffic. We also developed new programming abstractions that allow participating networks to create and run these applications and a runtime that both behaves correctly when interacting with BGP and ensures that applications do not interfere with each other. Finally, we also ensured that the system scales, both in terms of table size and computational overhead.

We are involved in several trial deployments of the SDX controller at various IXPs around the world, in collaboration with network operators.