VMware teamed up with Stanford and Berkeley on Tuesday to create an industry consortium around software defined networks, called the Open Networking Research Center. The company, famous for hypervisors that virtualize servers isn’t about to watch while companies attempt to build the same disruption in networking. The consortium counts CableLabs, Cisco, Ericsson, Google, Hewlett-Packard, Huawei, Intel, Juniper, NEC, NTT Docomo, Texas Instruments and VMware as its founding sponsors.
Much as server virtualization abstracts the hardware for the software that runs on it, allowing people to put different virtual machines on top of one server, virtualizing the network abstracts the cables and ports from the demands of the applications. But that’s not enough. To really achieve the flexibility that webscale and cloud companies demand, the network must be both virtualized and programmable.
The current enabler for this shift in networking is OpenFlow, a protocol developed out of Stanford and championed by a group formed last March called the Open Networking Forum. Many of the companies that have joined the VMware at the ONRC are also members of the ONF, including VMware. OpenFlow is a means to separate the intelligence associated with moving packets around the network with the gear that does the moving. At that point the intelligence can run on commodity servers, a factor that was seen as bad news for Cisco, Juniper and other networking companies which may see their margins drop and profits erode.
Allwyn Sequeira, CTO and VP for security and networking for VMware says that the creation of the ONRC is designed to push the concepts of software defined networks in general rather than the OpenFlow protocol. He said an SDN requires three elements: a controller that manages the networking gear; the controller protocol fused to control the devices (this may not be OpenFlow); and the apps on top of the controller that direct the network.
And he notes that OpenFlow adds the critical element of programmability to networking, likely residing in the controller with other protocols, but the creation of a software defined network doesn’t need it. He points to VMware’s own firewall and load balancing products as well as its VXLAN and other networking software as an example.
That’s a common argument from the industry, with folks from Juniper and Cisco pointing to their existing fabrics and products as an example of network virtualziation. So the key for the ONCR and the industry moving forward seems to be about how to make SDNs programmable since they already exist. Sequeira says this requires OpenFlow.
“We had a complete SDN stack with no OpenFlow and it was good enough for almost all the things that customers wanted to do,” Sequeira said. “There is the virtualization of the switches and firewalls and none of that requires OpenFlow. However, to program it requires OpenFlow even though even a little of that can be done without it.”
And while Sequeira recognizes the importance of OpenFlow, he doesn’t see some wholesale migration to OpenFlow-only networks. Current networking software and gear will work with OpenFlow but will not solely use the protocol. Which, given the statements by Urs Hölzle, SVP of technical infrastructure at Google, that there is no easy way for OpenFlow to communicate with other network protocols, have me thinking that we’re going to need more efficient ways to communicate from one network protocol to OpenFlow.
So the biggest battle in SDNs looks like it will be for the controller, which companies such as IBM, Nicira and Big Switch have developed. The question is: will OpenFlow be the lingua franca between rival controllers or will each strive to create it’s own proprietary network — programmable, running on commodity hardware, but still a fundamentally locked ecosystem?