Aruba: SDN tools to change wireless network models

The founder and CTO of Aruba wants the tools from software defined networking (SDN) to make access networks more flexible for business

Access networks are going through one of the biggest changes in a decade, according to the founder of Aruba Networks, and the model will have to adapt for the new way that people work.

Speaking at the company’s Airheads conference in Alicante, Spain, Keerti Melkote claimed the old way of creating a Virtual LAN (VLAN) for every type of connection could not continue.

“The fundamental design point [of access networks] was the office desk, where you would build out floors of office space based on users sat at desks with PCs and phones,” he said. 

“We would provision ports and the way we structured [the office] were based on VLANs… for PCs, VoIP, access VLANS.

“About 10 years ago [wireless] was considered not as secure as wired, so we segregated that on a third VLAN and guest users needed just the internet so that went on another VLAN. BYOD was not corporate issue, so we need yet another VLAN. You see what is happening, VLANs worked for a long time but it has mushroomed to a large degree and causing a big admin nightmare.”

But it wasn’t just the management issues that would cause concern; it was the type of applications which couldn’t easily be defined as the responsibility of one VLAN.

“The VLAN structure doesn’t work for the future, which is going to be about applications like unified communications,” said Melkote. “[Take] Microsoft Lync, which in a single app embeds all types of traffic. In a single Lync session you can have data file sharing, interactive desktop sharing, you can choose to do a voice chat and then say I want to do full on video.

“So which VLAN would you put Lync on? It doesn’t fit in that VLAN model.”

The founder and chief technology officer (CTO) said the corporate world was no longer about the office desk but about the office space – the campus where employees move around – so networks needed to be more context-aware when it came to devices, location and applications used.

“If you pull those together and call it a personal LAN, you can build your future vision around that,” Melkote said.

The way to make the network more capable of performing in this way will mean utilising techniques being raved about in the datacentre network environment – namely software defined networking (SDN).

Melkote said: “With VLANs, we used to go to the network and say light up an SSID [service set identifier], map it to a VLAN in the air, go to policy and go to filtering policy around routing – all this was manually done. But as we have seen in the past, things constantly change and the network needs to be reprogramming itself.

“What is needed in the mobile context is something that is a lot more programmable, where the infrastructure can be programmed on what is going on at that time on a per flow basis – take Lync and its five different flows – and this is where we think networks in the future will head – with software defined networking.

“What we want to do is leverage the tools to enable a similar programmable architecture for access networks.”

Aruba is keen to embrace open source protocols for this, from OpenFlow and OpenDaylight to RADIUS, and to enable its technology to work across multiple vendor routers. But the key is having an SDN-based control plane to control the infrastructure on an application by application basis.

“The layer above will connect with the network,” he said. “We will have APIs that [give] the ability to do security at the app layer, QoS at the app layer, even location [and] this is the foundation we are going to continue to innovate [in] over the next several years.”

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