Last week, an international group of researchers and vendors demonstrated international carrier-scale software-defined networking (SDN), exchanging 15,000 routes across a trans-Pacific link.
The partners – ESNet, switch vendor Corsa, the http://onosproject.org/ ONOS project, the Open Networking Foundation, AARnet and the CSIRO – fired up the demonstration that Internet-style international route peering can be brought into the new world of SDN.
El Reg spoke to AARNet network architect David Wilde about the demonstration, and what AARNet hopes to get out of SDN.
Busting out of the data centre
Wilde said the key focus of this demonstration was demonstrating that multiple parties – in this case AARnet, CSIRO and ESnet – could use SDN and OpenFlow across the WAN.
The interest here is straightforward: a lot of the focus of OpenFlow is on the data centre, where the number of switches and routes is relatively constrained – and everything's under the control of a single party.
“For someone like AARNet who runs a service provider network, I'm interested to see what capabilities and advantages that might bring,” Wilde said.
The Opening Networking Lab – On.Lab – also wanted to demonstrate that this kind of capability can be considered production-ready, Wilde said.
While 15,000 routes is “reasonable scale” Wilde said, he noted that work in the now-discontinued REANNZ SDN demonstrations* had reached around a million routes, “which is well and truly Internet-scale”.
The current demonstration involved Corsa switches in Sydney and in the US (at ESNet), and a Layer 2 circuit (on AARNet's chunk of Southern Cross) between them. The SDN software, including ESNet's Vandervecken label switch routing software, ran on virtual machines at ESNet and CSIRO (under the hand of Craig Russell).
While a live network might not involve so many organisations, Wilde said, the project “demonstrates that you can run the SDN controller separately to the switches that are actually passing the traffic” – even with so many organisations involved.
“The traffic doesn't go anywhere near the SDN controller. The Corsa switches leave it to the controller to sort out the control plane”, he said.
He explained that the attraction of SDN to an organisation like AARNet is management simplicity. Imagine a network that involves a port in a switch in Perth, connected to a router, passing traffic into a fibre link to a destination in Sydney.
Wilde says AARNet's interest it learning “what happens when you make your whole network look like a single device.”
Getting that unified view of the network should offer better scalability and control, he said – if that can be achieved at the wide-area or international scale that AARNet needs.
That, he said, is a key focus of AARNet's SDN testbed: “it works very well in a data centre or campus,” he explained.
He added that there are operational advantages (finding out why a link's up or down), and easier provisioning.
“To bring up a new service, you don't have to configure a bunch of devices – you tell the controller what to do, and the controller fans that out to the whole network”.