In this video from Dell's Network Field Day 11 (#NFD11) presentation, Madhu Santhanam demonstrates an interesting use case for the new OS10 switch operating system that was introduced at the event.
However, for any given site, only a small number the advertised prefixes are destinations for traffic. The challenge is to identify the most active prefixes so that they can be selectively installed in hardware tables. In this demonstration sFlow-RT is used to process the industry standard sFlow telemetry exported by the sFlow agent on the switch and compute the top N active prefixes. Every minute active prefixes installed and inactive prefixes are removed from the hardware using the Selective Route Push REST API.
Analytics driven SDN is poised to disrupt the router market, replacing expensive, custom hardware with commodity switches. Solutions like the one Dell presented are already in production. Last year, David Barroso gave a talk showing that 99% of Spotify’s Internet traffic was contained in only 20,000 prefixes and started the SDN Internet Router project which similarly combines BGP routing information with sFlow telemetry, but only updates the active routes every hour. In the Dell demo, updates occur every minute. The speed of response can be increased even further, the sFlow-RT Active Route Manager application detects and updates active routes within a second. Speed is important since the faster the application can react to changing traffic, the more effectively the hardware forwarding, opening up additional use cases for SDN routing.