Swinburne, Google target data centre congestion

Melbourne network engineers have partnered with Google in an attempt to address traffic congestion and packet loss in data centres.

The project

The project, led by Professor Grenville Armitage of the Swinburne University of Research, aims to control ‘microbursts’: sub-second traffic spikes that occur when multiple data streams without warning converge on a wire.

If the network switch closest to the end-point becomes congested, its buffer may overflow, causing packets to be lost, stalling the application.

Professor Armitage said the so-called ‘Microburst Congestion Control’ project with Google was an extension of Swinburne’s Cisco-funded ‘newtcp’ innovation into the TCP networking protocol.

The newtcp project

For the newtcp project, which commenced in 2005, Swinburne researchers studied delay-based and loss-based methods to determine a network’s optimal speed.

In the Linux community, NewReno has been replaced by CUBIC, a more aggressive TCP that Armitage said suited high-speed transfers within innovation laboratories nevertheless caused high latency in home networks with multiple users on a single internet gateway.

While loss-based methods like NewReno and CUBIC react to traffic spikes and packet loss, alternative, delay-based methods monitor variations in network latency to pre-empt spikes and adjust transmission speed consequently.

Armitage said delay-based algorithms had the potential to be "better-behaved" when sharing home internet gateways with interactive applications like VoIP (Voice over Internet Protocol) or online games.

But machines using delay-based TCP would lose out to machines using NewReno or the more aggressive CUBIC if they were to run on the same network.

The team planned to analyse anonymised data from Google’s production networks, test congestion management schemes and make recommendations to the search giant for the MCC project.

Results could potentially be applied to Google’s systems in a year, he said, highlighting the value of networking techniques as cloud computing becomes more pervasive.