Edge cloud, edge access and edge compute are all hot topics these days, but the Open Networking Foundation has a leg up on edge development due its past work on CORD (Central Office Re-architected as a Datacenter.)
At ONF Connect last week in Santa Clara, California, ONF members outlined some of their thought processes around the open source organization's multiaccess edge cloud (MEC) initiative.
Currently, MEC falls into ONF's "trailblazer" category, which means it's on deck for the current work that is being done across ONF's four reference designs. While ONF announced at last week's conference that the four reference designs—SEBA, NFV Fabric, UPAN and ODTN—are now out for review by its membership, MEC is a work in progress, albeit on a fast track.
"For almost a year we've been exploring with our partners, both our operator partners and our supply chain partners, what is the role that ONF can play in the context of this whole use case that is coming along that is called edge and edge cloud?" asked Guru Parulker, ONF executive director at last week's conference. "The fact that we have built CORD and some of these reference designs we find ourselves in the situation that maybe ONF can play a role in enabling an edge cloud. We have this thing that is taking shape that is called multiaccess edge cloud."
Following Parulker and Google senior product manager Prajakta Joshi's keynotes—Joshi helped developed CORD and ONOS when she was at ONF predecessor ON.Lab—ONF CTO Larry Peterson outlined MEC and the edge during his keynote presentation.
"It's really trying to put the puzzle pieces together and figure out how can we navigate this conversation basically between the data centers moving to the edge and the edges adopting data-center technologies," Peterson said. "These are two very strong bits of momentum and they are converging and exactly how they come together is a little bit tricky. It's access and software services in the same platform when you get out to the edge."
"And it's turned out the closer we come to realizing that, the more we understand that that's not an easy thing to do. It's not just a matter of taking a large data center and shrinking it down into a rack or half a rack. There's really something fundamentally different that's going on at the edge, at least when you start to bring access into it," he added.
Peterson said that while there are many different aspects to the edge, ONF, which is led by its operator members that include AT&T, China Telecom, China Unicom, Comcast, Deutsche Telekom, Google, NTT and Turk Telekom, narrowed its focus to the access edge. The access edge is where virtual network functions (VNFs), evolved packet cores, broadband network gateways (BNGs) and the end services co-exist at one location, according to Peterson.
"At ONF we've been asking, with our partners, two important questions," Peterson said. "The first question is: Is the edge, the access edge at least, just a smaller data center or is it something fundamentally different and qualitatively a different kind of platform? And the second question is: What is it that we do in the ONF community, this operator-led community, that's unique that we can bring to bear on this problem? Clearly a it's big space. We don't want to try to do everything, but what can we uniquely do?"
While the ONF has cast its lot with the access edge, Peterson said that wasn't the only type of edge, and that ONF needed to "need to figure out how to do end-to-end connectivity and this is where the service mesh comes into play."
"Well, when we started to look closely, you realize that we've got a really big challenge in front of us, which is that we're trying to simultaneously do two seemingly conflicting things," Peterson said. "So the first thing is clearly we're trying to move functionality for the sake of lowering latency closer to the end-user. You get it out of the data center, or at least fractions of what you've been doing in the data center, you get it closer to the end-user. And yet, in the access edge, that's where you've got mobility supported. So the advantages that the telcos have is not just the points-of-presence near the end users, they also support ability. And 5G is embracing this wholeheartedly."
"So how do you simultaneously move data to the end, to the edge, and allow for that functionality to be mobile? Simultaneously supporting those is really the hard problem. Up to this point, a cellular network had really been about mobile broadband—not mobile functionality. With mobile broadband, the function's been backed upstream somewhere. And so when you moved, you clearly had to move the broadband connection, but you didn't move the functions. But the second we start moving functions out to the edge and there's mobility supported, we've got to move the functionality as well," he added.
Peterson said that while moving to the edge access improves performance by being closer to the end users, that increased performance means not everything will be implemented on a x86 architecture. Edge access performance will be improved by using P4 in switches, and by "exploiting" graphic processing units (GPUs) and tensor processing units (TPUs.)
Peterson said the ONF needed to have a heterogeneous environment that's tailored toward low-latency applications, but access edge will also include working with different stakeholders that have responsibility for different pieces of the puzzle.
"This is not 'I own everything and I can solve the problem in a single-thrust' domain,'" he said. "We really have to deal with the different entities being able to contribute to, control, own, dictate activity at different points in this multiedge environment."
Peterson's third point about the access edge was that ONF's operator and vendor members need to deploy solutions that increase revenue streams.
"So monetization is clearly going to dictate that you want to customize and differentiate services. And probably even as fine a grain as the subscriber level," he said.
The fourth issue is a cost-engineering problem, which includes figuring out what goes to the edge and what needs to stay in a data center. The final point is coming to grips with the various controllers on the access edge. Peterson said it's going to be really important to figure how much autonomy there is at the edge, and how many of the controllers are local versus how many are global.
"So it's not too hard to take that set of factors and just translate it into a set of requirements," Peterson said. "Not surprisingly, we've been thinking about this very set of requirements for some time now. They've come into more sharp focus more recently, but if you go back to the earliest CORD requirement definitions, it's pretty consistent with what we just talked about here."
ONF is focusing a multitenant environment that could include cloud providers, edge cloud providers, over-the-top service providers, third-party providers and different telcos.
"These are all players that we have to account for, and we're just trying to not pick winners from a technology point of view at this point," he said. "We're trying to keep the space open."
Edge access in play
Parulker said that Google's Prajakta Joshi was helpful in connecting ONF with Google Cloud, which led to a recent demonstration between the Google Cloud platform and ONF's CORD. While ONF has a laser focus on moving its reference designs forward, it's clear that edge access is in play.
Earlier this year, the ONF restructured itself to better serve the needs of its operator members. Comcast, which is championing the Trellis reference design, liked what it saw in terms of ONF's pursuit of access edge technologies. With the constant increase in bandwidth demand, the move to distributed access architectures and all-IP, Comcast is actively pursuing edge solutions.
"We like that it (ONF) is targeting the edge in the access network," said Comcast's Rob Howald, vice president of access architecture, in his ONF keynote. "Right while we're in the middle of looking at what we should be doing for edge and access at Comcast, lo and behold, there's an organization, this organization, that's focused there as well. Obviously, it's been here longer than we've been here, but that part of this mission—focus on the edge and the access—that's also something that we find that may be synergistic with what we're trying to do."