One of the great debates which will help to shape next generation mobile networks and services concerns the growing role of open source in the cellular world. Some operators have raced to embrace open source technologies in the network, to accelerate the progress towards virtualization and software-defined networking (SDN). Open source platforms for hardware elements like base stations and radios are even starting to emerge.
But there are risks as well as rewards in the open process, and most players are looking towards a hybrid approach where the speed and broad-based innovation of open source can be tempered by the clear direction and strong quality control of a formal standards process. Indeed, the Linux Foundation itself has published a white paper outlining how different open source initiatives, and standards bodies, could work together to avoid duplication or fragmentation (see below).
Even one of the great cheerleaders among the major MNOs, AT&T, has recently been showing some nervousness about wholehearted commitment to OpenStack, while an executive from PCCW in Hong Kong called open source “an overrated necessity”.
Yet many MNOs would be more easily reconciled to this approach if they were confident of being able to control it – as AT&T did when it placed its own ECOMP orchestration software into the open source world, a tactic which Sprint has now emulated with its NFV/SDN mobile core reference design, C3PO.
On the sceptical side of the ring, Shahar Steiff, an assistant VP at PCCW, told this week’s TMForum Live event in France that open source “only provides half of the things we need – the code but not the information model or standards. Yes, it is faster than proprietary code, but with a standard I don’t care if it is open source or proprietary code.” And he added that, while open source was ‘free’ upfront, it cost a great deal to implement effectively in an operator’s systems.
Even AT&T, whose ECOMP is now the foundation of the open source initiative ONAP (Open Network Automation Platform), has some doubts. Rupesh Chokshi, an assistant VP at the telco, told LightReading that open source will not deliver the same “quality, performance and reliability” as proprietary technologies, or those defined by conventional standards bodies, and this will be particularly sensitive in the area of security.
And when LightReading’s Ian Morris asked Chokshi whether OpenStack (on which ECOMP is based) was “here to stay” at the carrier, the executive responded: “It is difficult to say whether it will be replaced or not but right now that is what we have in the infrastructure delivering services. If there are better ways of doing things those will be part of the ongoing process.”
Some have speculated that AT&T will evolve beyond the OpenStack cloud computing platform in time, having expressed interest in alternative approaches built around microservices and containers (though most of these are open source too). Peter Willis, the BT executive who launched a high profile attack on the shortcomings of OpenStack in a carrier environment (despite BT being an early and strong supporter), has recently been talking up the advantages of containers too.
At the recent NFV World Congress in Silicon Valley, BT was, however, speaking up for open source in general, though with warnings that it is not an easy option, echoed by speakers from Orange and Telefonica. Patrick Lopez, Telefónica’s VP of networks innovation, said supporting open source had involved a large amount of inhouse work to simplify the architecture. “To do that, we have refused to go see a large vendor or large integrator and give them a mandate. We decided to do it ourselves and learn ourselves,” he told the event. The cost savings operators want from open source, automation and virtualization will only happen if they “get their hands dirty” and learn programming, he added.
Mansoor Hanif, director of BT’s converged networks research lab, said he liked the fast pace of open source, but had needed “a whole new generation of network engineers”, and was concerned about interoperability.
The ultimate ‘hard work’ approach to open source must be to develop an entire platform and then contribute it to the process as AT&T, China Mobile and Telefonica have done in the field of management and orchestration (MANO) for virtualized networks. Now Sprint is following suit with its C3PO (Clean CUPS Core for Packet Optimization), an open source mobile core reference solution.
This harnesses 3GPP approaches to CUPS (control and user plane separation, a hallmark of SDN) but also open source work and Sprint’s own developments. The operator’s COO – Technology, Günther Ottendorfer, said: “C3PO revolutionizes the network core and it’s part of our expanded toolbox of solutions to meet the coming wave of data in the years ahead. C3PO is an important part of our NFV and SDN initiative, enabling Sprint to adapt more quickly to market demands and scale new services more efficiently and cost-effectively.”
The result of a four-year collaboration with Intel, C3PO is designed to ease bottlenecks in mobile core packet performance by independently scaling the data plane and control plane. It collapses multiple EPC and SGi LAN elements in a single data plane instance.
Intel Labs built the core control plane and data plane virtualized EPC applications, and Sprint developed the SDN controller enhancements.
The EPC application code from Intel is available via the CORD project in ON.Lab, and the SDN plug-ins from Sprint are available via OpenDaylight. Next steps will include work to extend the code to new use cases, including some in the Internet of Things.
Sprint’s decision to release its code on an open source platform is part of the carrier’s commitment to advancing the industry, said VP of technology Ron Marquardt.
“Open source is a model that works,” he wrote in a blog post. “Open source development allows for very rapid innovation, with a vibrant community providing a high volume of contributions at a relentless pace. The open source model streamlines processes and removes confusion on specifications and their interpretation because the actual implementation is what matters, not the verbiage of a written document … The lines between open source prototypes and normative standards are blurring, and Sprint will continue to contribute to these advancements in our industry.”
Meanwhile the Linux Foundation, which hosts several important carrier-oriented open source projects, has been calling for telecoms standards bodies to work together with the open initiatives to accelerate progress and avoid damaging splits or fragmentation. Multivendor interoperability and automation across multiple NFV/SDN efforts will require close coordination, says a new white paper from the Foundation, as well as recognition, on both sides, of what each does best.
The white paper, entitled ‘Harmonizing Open Source and Standards in the Telecom World’, points out legal and intellectual property challenges and ways to work together, but also builds on a unified architecture which the Foundation’s head of networking, Arpit Joshipura, presented at the recent Open Network Summit. That aligned various open source groups with existing standards bodies and pointed out areas where they were overlapping or duplicating effort.
One of the Foundation’s goals for this year is “harmonizing” the efforts. As Joshipura put it: “There’s a place for standards and there’s a place for open source, and the two of them can be the best of friends.”
He said: “As a neutral party, we would like to facilitate those conversations, but some of that may take place in the standards groups themselves,” Joshipura said. “The first step is project by project, standard by standard. We will look at introduction goals, what are complementary things.”
He added: “We agree on the end results but the paths are different on how we get there and when the paths are different, it’s important to get terminology aligned and processes aligned and start the dialog for the actual architecture and the integration. Open API does not mean the same thing when I say it as when a vendor says it or when another open source project says it”
The major open source networking initiatives hosted by the Linux Foundation include OpenDaylight, OPNFV, ONAP, FD.io, Open vSwitch, OpenSwitch, IO Visor, ON.Lab, CORD and ONOS.