The progress in deploying virtualized networks based on NFV (Network Functions Virtualization) has been slower than hoped for many reasons, not least the technical and cultural challenges of this huge architectural transition.
Another key factor has been the misalignment between traditional standards processes and the increasingly influential open source community. Operators are looking for the improved economics of a fully open platform, but there is a wait before they will trust these untried systems with their main commercial networks, and also while they wait for a new generation of solutions based on fully cloud-native principles rather than first generation virtualization.
An important step forward has been taken to bring old-style and new communities together in enhancing the NFV platform. This is a collaboration between the most traditional of telco alliances, the GSMA, and the main open source player in telecoms, the Linux Foundation and its Networking Fund (LFN, and umbrella for many projects including the AT&T-initiatied Open Network Automation Protocol, or ONAP, and ORAN).
The new partnership will be labelled the Common NFVi Telco Taskforce (CNTT) and will be hosted by the GSMA with “input” from LFN. The aim is to define common NFV infrastructure (NFVi) reference architectures which will be submitted to LFN for testing and verification via its OPNFV (Open Platform for NFV) verification program (OVP).
Arpit Joshipura, general manager for networking, automation, edge and IoT at the Linux Foundation, explained that LFN will bring the software, automation, tools, and infrastructure testing “that will actually set up the framework to implement the common NFVi”. Its members will also offer up the necessary upstream and downstream code including virtual infrastructure managers (VIMs), ONAP and VNFs “to create a complete end-to-end automated test system”.
“Having an NFVi framework was a great first step but bringing the community of major carriers together in a neutral governance like the Linux Foundation was required,” he said in an interview.
This is important for bringing the very different traditions of MNOs and of the open cloud world closer together. The gulf between the two communities has slowed progress in several key areas of virtualization, particularly the management and orchestration (MANO) of all those virtualized components and functions. The split between ONAP, the Linux Foundation would-be standard for MANO, and ETSI’s Open Source MANO (OSM) remains unresolved despite some steps towards greater cooperation between the two groups.
However, the CNTT is not all good news for anyone dreaming of a fully open, cloud-style ecosystem breaking down the barriers around the telecoms network. The participation of the GSMA is a recognition that the open processes will not go away, and that its members are very keen to embrace them in order to drive down costs and accelerate innovation. But it could just have signed up to support an initiative run by the LFN. Instead, the CNTT is explicitly an attempt to ensure that the large operators tap into the benefits of an open platform, but also retain full control of its direction.
The alliance was first mooted at the Open Networking Summit in San Jose, California in April, and 10 large telcos expressed support, and explained in a presentation that they needed to have “more control” of how an NFVi standard evolved. Those operators are the usual suspects in shaping a more open ecosystem firmly in their own image – AT&T, Bell Canada, China Mobile, Deutsche Telekom, Reliance Jio, Orange, SK Telecom, Telstra, Verizon and Vodafone.
The aim of the new project, as revealed back in February by LightReading, is to support three NFVi architectures – for network-intensive applications, compute-intensive applications and ‘nominal cases’ (general workloads including non-specialized IoT). The architectures will be defined by GSMA and published by OPNFV. Vendors will certify their virtual network functions (VNFs) against the target architectures through the OVP process and supporting telcos will then be able to mandate OPNFV-certified VNFs in their networks, and so drive interoperability and the improved economics of a multivendor, open platform.
This aims to address one of the biggest barriers in the way of mass-scale virtualization, that each operator currently has a slightly different NFVi implementation. That makes it hard to use VNFs from multiple vendors in the same platform, and it adds to suppliers’ cost and time to market as they have to test their software individually for each telco.
The scale of the problem is shown in the OPNFV itself. Conceived by the Linux Foundation to create a common “reference NFV platform to accelerate the transformation of enterprise and service provider networks”, in fact many companies have contributed their own variants and it has ended up with about 60 NFVi configurations, a far cry from the three envisaged by CNTT.
Of course, that highlights the downside of the open source approach – the risk of fragmentation if a project does not strike the right balance between commonality and open innovation. In a wild west environment like this, it is natural that operators fall back on fully unified standards processes and insist on taking the driving seat in the open communities.
Rabi Abdel, SDN/NFV lead architect at Vodafone Group and vice chair of the LFN compliance and verification committee, said: “The CNTT will make OVP more efficient and effective.” He told Heavy Reading: “We need a mature standard for NFVi. Open source is great at making fast development, but with the GSMA we will be able to reach a more stable level of standardization and it will be influenced mainly by operators [not vendors].”
But there appears to be no involvement in the new initiative by ETSI, creator of the original NFV specifications and guardian of 3GPP standards. That does not bode well for possible closer cooperation between the ETSI and LFN camps in areas like MANO. It also suggests that the operators would rather work through GSMA, their own trade association, than a broader standards effort in which traditional vendors are powerful.
Abdel said: “We are leveraging a lot of the work done by ETSI but the main focus of the work for CNTT is to reach a clean level of abstraction between the NFVi and the VNFs. That means defining interfaces and APIs that are architecture agnostic and regardless of whether we are using virtual machines or containers.”
Joshipura added: “We do not expect roles to change as our vision is quite complementary – create specifications in standards development organizations and implement in open source with a quick and neutral feedback loop.”
The CNTT will hold an inaugural face-to-face meeting on July 23-25 in Paris, to further discuss reference model development, and analyze integration requirements with OPNFV projects, processes and procedures.