This article was authored by John C. Tanner, and was originally posted on telecomasia.net.
You can have SDN without NFV, but you can't have NFV without SDN – not if you want greater service agility and new revenue streams, said the head of the Open Networking Foundation.
Speaking at the SDN & Openflow Asia-Pacific Congress in Hong Kong Wednesday, ONF executive director Dan Pitt said that while the foundation is committed to working with the ETSI NFV ISG to help develop NFV, he warned operators that NFV is only a partial solution to the overall problem of virtualizing telecom networks to make them more agile and programmable.
“There are complaints from so many operators that they have so many appliances – as many as they have switches and routers – so they want to get rid of those,” Pitts said. “But it’s only a partial solution to take an appliance out of the network and replace it with a bare-metal server running Linux, because they still require separate management and because they’re out in the field, it’s a whole maintenance question.”
Pitt said that NFV will help operators dramatically reduce capex, but not opex, and it doesn’t really enable service agility and new revenue streams the way SDN does.
Pitt also argued that NFV has a limited shelf life on its own because certain network functions will eventually become obsolete as networks become primarily software-driven.
“I think we’re going to get a lot of mileage out of NFV for about ten years, and after that we’re going to realize that we’re just virtualizing artifacts of the old hardware-defined networking days, and we don’t need to perpetuate those any longer,” he said. “We’re going to have applications that need certain kinds of connectivity – that’s what the network does – and we’ll eliminate all the intermediate artifacts.”
Pitt added that only around 10% of the appliances that telcos want to virtualize can be virtualized just with software running on an x86 or an ARM processor. “The other 90% or so require cooperation of the forwarding plane, and that’s where SDN comes in.”
Pitt’s talk followed a presentation from Hideo Ishii, VP of network engineering and architecture for Pacnet, who said that that from a carrier perspective, SDN and NFV are complementary, but both can run independently of each other.
Pitt disagreed. ”People will secretly admit that most VNFs require cooperation of the forwarding plane and therefore SDN. The reverse is not at all true.”
The ONF signed an MoU with ETSI NFV ISG in March to work together on NFV, with focus on three elements – virtualized network function forwarding graphs, establishing persistent and secure communication between VNFs, and SDN for configuration and control of NFV.
Pitt made clear that he was happy to work with ETSI, and that the NFV ISG is “the best thing ETSI has done in 25 years”.
“NFV needs SDN, and carriers need NFV. It’s a simple logical progression,” he said. “The will is there on both sides – we want to help them, they want us to help them. And SDN really as a foundation for supporting NFV is the best, purest and cleanest way of connecting the control plane where the VNFs live and the forwarding plane.”