Thanks to OpenFlow, Meru Networks says it won't need to hatch a unified wired and wireless network management fabric
to keep up with competitors.
Meru is pursuing an SDN wireless approach that will use OpenFlow controllers to link together wired switches and wireless access points (APs) into a single manageable entity.
As an initial step, Meru became the first WLAN provider to receive OpenFlow 1.0 conformance certification from the Open Networking Foundation (ONF) for its Wi-Fi equipment. Meru's MC4200 mobility controller and AP832 802.11ac access points can interact with any SDN controller that speaks OpenFlow as a southbound protocol.
"Wireless has been deployed as an overlay network where you have a controller and APs," said Ajay Malik, senior vice president of engineering and quality assurance at Meru. That controller implements traffic and management policies to APs. Meanwhile, in an SDN environment on the wired side of the picture, "the forwarding plane of every wired device can be controlled by the SDN controller."
The goal now would be to have one SDN controller that can collect the topology of both wired and wireless networks to implement unified policy, provisioning and management. Meru will enable two methods for this kind of centralized control. In one scenario, the SDN controller would communicate with the WLAN controller or WLAN switch, which would in turn communicate with the APs. In the other model, an SDN controller would speak directly into APs, Malik said.
Network engineers will probably find the first scenario more appealing, said Rohit Mehra, vice president of network infrastructure at research firm IDC. WLAN controllers have lots of radio frequency (RF) management and interference prevention functionality that SDN controllers are not ready to replace, he said. In the long term, however, OpenFlow could become a universal standard that allows SDN controllers to speak to any wireless AP, which could also lead to elusive WLAN infrastructure interoperability, Mehra explained. Currently, every WLAN vendor uses proprietary protocols between their controllers and APs.
Meru has already begun to demonstrate its SDN wireless through a Lync quality-of-service application.
"When the [WLAN] controller gets a notification from the Lync server that a particular call quality is not good, the application sends an instruction to the SDN controller to change the quality of service for this call. The SDN controller checks whether the bandwidth is right for this call to make it successful. The SDN controller has all the topology and it will send an instruction to increase bandwidth to improve call quality," Malik explained.
How one university will apply Meru's SDN wireless
At the University of Houston, Charles Chambers, manager of network planning, has been testing SDN in cloud computing clusters as part of a larger project with Global Environment Network Innovations (GENI). His SDN involvement brought him to the Open Networking Foundation last year where Meru was demonstrating its SDN wireless environment.
The university was already a big Meru shop, so Chambers' was immediately enticed by the possibility of simplifying wired and wireless management.
"Right now I am managing a network with close to 6,000 network elements between the access points and switches and routers and firewalls," Chambers said. "We use SNMP [Simple Network Management Protocol] to monitor and manage, and we have configuration management tools, but they are all sub-optimized."
A centralized SDN controller that communicates with both wired and wireless networks would bring real-time awareness that SNMP, for example, could not. Chambers and his team will start by implementing a subset of the wireless infrastructure with an SDN controller for testing. First he'll monitor how well the controller accounts for the topology and connectivity, and then he'll test specific applications.
"One of our first apps will be to do pseudo wires to allow me to connect to a large number of points across campus and drag data back to the data center where I can have a Wireshark-based device look at specific traffic," Chambers said. This approach could replace the need for IT staff to tote around laptops and plug them into ports in various buildings to do packet captures.
Meanwhile, a researcher on Chambers' team is already testing SDN for an emergency management portal. This work can be extended into the wireless environment.
"A lot of information can be gotten from all these mobile devices that are floating around on our wireless campus [ by using a centralized controller]. I can see where people are congregating or dispersing from, and that can give me information about an emergency. It's hard to get [that information] out [of] traditional SNMP-managed, CLI-configured proprietary tools," Chambers said.
SDN unified wireless will require OpenFlow-friendly switches
In order to implement OpenFlow-based unified wired and wireless, enterprises will have to commit to implementing OpenFlow switches.
That could be an issue, considering so many vendors are testing out multiple alternative southbound protocols for SDN environments. However, Meru's Malik said plenty of hardware vendors have production-ready OpenFlow switches, including NEC, Brocade, Extreme and HP. Most of these providers have hybrid stories and this lends itself for integrated wired and wireless programmability.
Mehra said Meru made a safe assumption in using OpenFlow.
"While OpenFlow may not have the exclusive prominence it had two years ago, our [recent SDN] survey shows that in a market with quite a proliferation of different protocols, about 35% of users expect OpenFlow to be the protocol of choice," Mehra said.
Chambers and his team will implement a "very thin hybrid OpenFlow environment" and are already testing OpenFlow switches from Brocade and Dell. The important factor to Chambers is that "generic controllers," such as OpenDaylight, support OpenFlow, which means he can implement any such controller and focus instead on the wide array of applications that live on top of those controllers.
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