The early results on telecom's use of open source are in and it's been a bit of a bumpy road thus far. One thing is clear: The companies that are moving forward are those willing to get their hands dirty.

Speakers from BT, Orange and Telefónica said at last week's NFV World Congress in San Jose, Calif., that open source is a vital component to their NFV plans. As early adopters, though, they had to do some work. Telefónica SA (NYSE: TEF), for instance, got around interoperability problems by taking the DIY approach.

"We have consciously tried to simplify, as much as we can, the architecture," said Patrick Lopez, Telefónica's vice president of networks innovation. "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."

Of course, Telefonica was not alone in that. AT&T developed its own entire MANO platform and then decided they needed help from the open source community and moved the ECOMP platform into open source, where it subsequently merged with Open-O to create the Open Network Automation Platform (ONAP) . (See Will ECOMP Be the Alpha MANO? and MANO Marriage: ECOMP, OPEN-O Converge as ONAP.)

The changing level of engagement reflects the reality that carriers and open source never had to mix to this extent. That is one explanation for why operators themselves have triggered the creation of multiple open source MANO projects, with some overlap, not to mention driving the formation of OPNFV to stitch the complex pieces of the original ETSI NFV architecture, along with diverse open source pieces, into a reference framework. Even with all this activity -- or in some cases, because of it -- interoperability is a looming question as well. (See Together, We Can Build the Telecom 'App Store' and Time for a Telecom Reboot.)

Thus, the key factor seems to be that open source software isn't meant to be a passive undertaking. Opex savings from automation and virtualization won't appear "unless the service providers get their hands dirty" and learn programming, Lopez said.

"Our team is composed of programmers and UX [user interface/experience] experts, and the objectives I gave to the team is: Go and measure what the benefit is to have a programmable network if you know how to program," he said. "I think that's what sets the project apart."

Telefónica took responsibility for bringing containers and Kubernetes orchestration into its virtual CPE project, and the carrier acted as its own integrator when tapping commercial products for security or for an optical line termination (OLT) unit.

Contain your enthusiasm
Mansoor Hanif of BT Group plc (NYSE: BT; London: BTA) took a similar view, with an added dose of skepticism.

Hanif, who joined from EE and is now director of BT's converged networks research lab, does believe in DevOps and a software-driven culture. "We need a whole new generation of network engineers," he said. He expects containers, in particular, to be a vital piece of future NFV deployments.

But his enthusiasm for open source is tempered. While he likes the fast pace, he noted the interoperability problem -- a time gap between finishing open source software and finding out whether it matches other companies' products. "We don't want to slow things down, but we need to have interoperability," he said.

In the other direction, he noted that "there are areas where it's important to work this way." Open source efforts such as the Telecom Infra Project (TIP) and Voyager, the white box optical transponder that Facebook contributed to TIP, got the job done in a way that a slower standards effort wouldn't have. (See Facebook, TIP Splash Some Open Sauce on Optical Networking and Voyager Trial 'Very Cool' for Telia Carrier.)

Orange (NYSE: FTE), which is deploying a virtualized CPE to go with its Easy Go service, is a big believer in open source and hopes to take advantage of it as Easy Go begins to encompass more virtualized network elements. Jehanne Savi, executive leader of the carrier's On-Demand Networks Programs, noted that Orange is counting on OPNFV to help advance the NFV ecosystem.

OPNFV is "not completely stabilized" and "not completely mature as an ecosystem," she admitted. Still, she said, "we should bet on stabilizing what we have" rather than giving up on the framework.

She noted the importance of interoperability and of certifying NFV software, warning that having too many unconnected options would be unsustainable in terms of business practicalities. Savi favored OPNFV as a forum for taking care of these issues, interoperability in particular. Alternatives would include the New IP Agency, which is working on interoperability at the management and network orchestration (MANO) level. (See The NIA Can Help Make NFV a Success.)

— Craig Matsumoto, Editor-in-Chief, Light Reading