Network Virtualization Initiatives Propel NSPs Closer to Strategic Transformation

Industry-Wide Open-Source Agenda Moves into Higher Gear

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NSPs have been working through the Open Networking Foundation (ONF).

Collaborative efforts aimed at facilitating use of open-source technology in network virtualization have brought telecom, cable and mobile operators to the brink of executing new strategies that promise to be as disruptive as anything yet seen in the broadband era.

Robert Howald, VP, network architecture, Comcast.

In a display of unprecedented cross-sector cooperation Tier 1 network service providers (NSPs) have been working through the Open Networking Foundation (ONF) and its offshoots to lower service migration costs by developing templates for solutions encapsulated as VMs (virtual machines) or container microservices, depending on the choice of virtualization modes, that can be implemented on disparate infrastructures. As a result, cable, telephone and mobile operators find themselves entering an intense innovations-based competitive environment where old network-based distinctions will lose their relevance.

“The ONF has come a long way since its founding in 2011,” said Nick McKeown, a professor at Stanford University and ONF board member, at the outset of the latest ONF Summit in late March. “Like all the best disruptions, SDN (software-defined networking) changed who is in control, putting network owners and operators firmly in charge of their networks for the first time. While transformation takes time, the keys are steadily being handed over, allowing a Cambrian explosion of new ideas to take root, and breaking the stranglehold of the old ways.”

Several acronym-laden initiatives pertaining to every aspect of what it takes to turn networks into automated Ethernet pipes carrying IP traffic to and from intelligent edge interfaces with wireline and wireless access links are coming to fruition all at once, feeding proof-of-concept tests and trials among NSPs worldwide. According to ONF, among 18 Tier-1 operators actively testing and trialing this strategy at least two are moving into production with projects in 2018.

One of those might be Comcast. Speaking at the ONF Summit, Robert Howald, vice president of network architecture at Comcast, noted that with DOCSIS 3.1 now installed on close to 100 percent of the MSO’s DOCSIS footprint the company hopes to begin deploying what is known in cable circles as Distributed Access Architecture before the year is out, possibly with reliance on key components in the ONF protocol portfolio.

Once cable optic-to-RF conversion is pushed into node-based Remote PHY modules, “what’s left behind is really a switch, route, compute, storage, processing machine,” Howald said. “Suddenly there’s a very large switch fabric with millions of Ethernet ports and lots of 10 GigE connections.

“That kind of scale sort of suggests that you want to have some automation control over that with some of the tools that are available here at ONF,” he continued. “We’re taking a good hard look at Trellis and ONOS to be those tools.”

ONOS is the Linux Open Network Operating System, one of two ONF-endorsed SDN controllers, the other being OpenDaylight (ODL). Trellis is the SDN-based multi-purpose spine-leaf switching fabric used with the ONOS controller to orchestrate white box switching hardware in support of the ONF’s edge virtualization initiative known as CORD (Central Office Re-Architected as a Data Center).

Notwithstanding the uncable-like nomenclature, Comcast is a participant in CORD, which is now a full-fledged independently operated coalition with 160 member organizations worldwide. In addition to Comcast these include major NSPs like AT&T, Verizon, China Unicom, Telefonica and NTT as well as vendors such as Cisco, Nokia, Ericsson, Samsung and Intel.

CORD establishes a reference architecture utilizing commodity servers, white-box switches, various disaggregated access technologies and leading open-source software to support 25 VNFs (virtual network functions) that facilitate aggregation of residential, enterprise and mobile services onto one platform. Operators can differentiate their service offerings by chaining various VNFs into unique service definitions, which can be bundled into single instantiations on COTS appliance clusters.

As Comcast implements DAA it will be able to utilize 16 to 32 wavelengths per fiber to digitally deliver 10 GigE two-way feeds per wavelength to each fiber-deep node at distances up to 80 or more kilometers, Howald said. “This will allow us to do things more scalably and to migrate services more quickly,” he noted.

With release of the latest ONF specifications the main goal collectively is to “get platforms stable in a production environment,” he added, “We’re impressed with what we’ve seen on the proofs of concept and trial work we’ve done. But the hard works is really left to be done. We haven’t really accomplished anything until we get this in front of customers.”

For that to happen Comcast must be sure implementation of DAA and the virtualized components can be done without interrupting existing customer service flows. “That’s a big goal for us, and we’re still a ways away from getting the platform we need to be at that level of stability,” Howald said. “We all want to get to production. We think we have a shot to do that with some of these platforms this year.”

The scale of commitment to such efforts leaves no doubt the industry has reached the threshold of a worldwide transformation in networking technology that will shape the competitive landscape for years to come. According to research conducted by Heavy Reading, nearly 40 percent of all residential, wireless and enterprise customers, collectively, will be served by edge facilities using CORD by mid-2021.

Seventy-percent of respondents to a recent global IHS Markit survey said they plan to deploy CORD in their edge facilities at some point. These efforts are part of a $300-billion annual commitment to spending on edge infrastructure, which represents about 80 percent of all NSP capital outlays, according to IHS.

Like Comcast and many other NSPs, AT&T is not wasting any time moving to a next-generation virtualized networking platform. Addressing the ONF Summit, AT&T CTO and president of AT&T Labs Andre Fuetsch, the current ONF board chair, said his company has begun rolling out more than 60,000 white-box routers on its mobile infrastructure utilizing the in-house developed Disaggregated Network OS (DANOS), which the carrier has made available to the open-source community.

“These machines will be at the core of 5G build,” Fuetsch said. “People think 5G is about speed, better latency, etc. But for us it’s this ability to move these different functions and workloads dynamically, elastically, to meet” any service requirement.

The need to aggregate massive amounts of traffic generated by small cells in the 5G infrastructure will require operators to set up what amounts to micro-datacenter facilities to serve fewer customers. These refrigerator-size or even smaller appliances may be co-located with traditional cell towers or closer in with pole-mounted antennas that communicate with clusters of small cells. Field tests are underway to get a better understanding of what the 5G edge architecture looks like with expectations that the combination of more centrally located control planes managing data planes on distributed hardware will minimize costs and unit sizes.

AT&T is also moving to a CORD-based optical access system architecture with the goal of disaggregating PON functions into functional modules with open interfaces that will support “access-as-a-service” use cases.  Here the company is employing another in-house component available to the open-source community called VOLTHA (Virtual Optical Line Terminal Hardware Abstraction), which supports the CORD Project objective of multi-vendor, multi-domain access-as-a-service reference implementation for the central office.

VOLTHA provides isolation between an abstract, vendor agnostic PON management system and a set of vendor-specific PON hardware devices, explained Eddy Baker, assistant vice president of technical design and architecture at AT&T Labs. “AT&T has worked closely with ONF to develop and test an ONOS and VOLTHA software solution to abstract and hide the lower level details of PON OLT and ONU (optical network unit) hardware and operation,” Baker said.

These 5G, PON and other edge-based virtualization initiatives are integrated at the core through an Open Source Access Manager that runs on the Open Network Automation Platform, a critical project within the Linux Foundation that also originated with AT&T. ONAP runs in a cloud environment in Docker containers, automated and managed by Kubernetes as a global orchestrator with CORD as the intelligent edge.

These capabilities point to another major aspect of what the virtualized edge environment is bringing into play, which is the B2B opportunities NSPs hope to exploit through intelligent networking. What began over two years ago as a smattering of NSP initiatives aimed at transforming edge infrastructures for such purposes has burgeoned into a worldwide movement, including increasing engagement in previously reported projects like the buildout of cable edge datacenter facilities and the Ericsson-driven global Unified Delivery Network (UDN) alliance.

At the outset of the ONF Summit the organization announced it was expanding its approach to helping the industry move open-source, next-generation SDN and related data-plane NFV (network function virtualization) solutions into production in their networks. The ONF operators, AT&T, China Unicom, Comcast, Google, Deutsche Telekom, NTT Group, Telefonica, and Turk Telekom were reported to have jointly developed and unanimously approved the plan, which involves development of reference designs (RDs) for various platform components that will be deployed across multiple operators.

“Reference designs will clearly indicate to the market what operators are planning to deploy, ONF said. “With specific operators backing specific RDs, there should be no doubt about what platforms are gaining traction in the industry.”

The organization has created a new technical leadership team to identify the use cases that will be assigned to specific RD teams tasked with developing blueprints outlining how a selection of components can be assembled into platforms to address specific operator needs. “We have seen the positive industry impact of RFPs mandating vendors’ adoption of open platforms,” said Patrick Lopez, vice president of networks innovation at Telefónica. “[The RD initiative] will give vendors clear direction and the ability to leverage their investment in open-source platforms across a multitude of opportunities.”

Similar sentiments were voiced by Xiongyan Tang, chief scientist for network technology research at China Unicom. “We believe this will create the critical mass needed to get the supply chain to start building solutions based on an open platform that we need,” he said.


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