Low-latency Network Monitoring via Oversubscribed Port Mirroring

Abstract

Modern networks operate at a speed and scale that make it impossible for human operators to manually respond to transient problems, e.g., congestion induced by workload dynamics. Even reacting to issues in seconds can cause significant disruption, so network operators overprovision their networks to minimize the likelihood of problems. Software-defined networking (SDN) introduces the possibility of building autonomous, self-tuning networks that constantly monitor network conditions and react rapidly to problems. Previous work has demonstrated that new routes can be installed by an SDN controller in tens of milliseconds, but state-of-the-art network measurement systems take hundreds of milliseconds or more to collect a view of current network conditions. To support future autonomous SDNs, a much lower latency network monitoring mechanism is necessary, especially as we move from 1 Gb to 10 Gb and 40 Gb links, which require 10x and 40x faster measurement to detect flows of the same size. We believe that networks need to, and can, adapt to network dynamics at timescales closer to milliseconds or less.