Industry association MEF today released the draft of its SD-WAN service definition standard, which describes the requirements for an application-aware over-the-top WAN connectivity service. This standard will lay the groundwork for SD-WAN stakeholders to develop more robust and application-based SD-WAN services.

MEF plans to have the full official standard published in July following the board approval of the proposed standard.

According to Stan Hubbard, director of communications and research at MEF, the standard is part of “what [MEF] would call groundbreaking work to define an SD-WAN service to address one of the biggest obstacles that’s impacting the SD-WAN service market growth, and that’s the lack of common terminology among ecosystem stakeholders.”

MEF embarked on the journey toward SD-WAN standardization somewhere around 2017, starting a MEF 3.0 multi-vendor SD-WAN implementation project in May 2018, and creating a technical specification for this service definition in October 2018.

The main driver behind creating this standard is to “enable the industry stakeholders to use the same terminology when buying, selling, accessing, deploying, and delivering SD-WAN services,” says Hubbard, adding that the service definition will serve as a foundation for accelerating SD-WAN sales, market adoption, and a certification for SD-WAN services for service providers.

As the SD-WAN market grows both in demand and number of vendors, it is becoming increasingly difficult for end-users to separate actual functionality from buzzwords. Using common, standardized SD-WAN definitions will “reduce market confusion around the service components, the core capabilities, and the various concepts associated with SD-WAN,” said Hubbard.

MEF was first founded to create a similar service definition standard for the carrier Ethernet market and has traditionally focused on connectivity and transport services. According to Ralph Santitoro, head of SDN/NFV/SD-WAN services at Fujitsu and founding member and distinguished fellow at MEF, SD-WAN is the first service in which the group has focused on more than connectivity. It is also focused on defining policies for applications and “everything above connectivity,” he said.

Because of this, SD-WAN is the first specification coming out of MEF’s relatively new application committee, which Santitoro adds is a critical change of direction for MEF that moves the group toward where the market is going — and away from just connectivity as network services transition to be more in line with cloud services.

“SD-WAN is the first type of network service that follows that methodology where it's much more automated, it's orchestrated, you can turn it up very, very, quickly. It doesn’t require peering agreements with other operators, so just like in a cloud service, you can turn it up very quickly through a portal,” Santitoro said. “That’s our goal with SD-WAN services is to be able to turn up a service literally like you turn up a cloud service with all that automation.” This also means that providers and vendors will be able to bring SD-WAN services to market much more quickly.

The service definitions and attributes are the result of “thousands” of comments from the group’s members and include contributions from more than 30 MEF members, including vendors and service providers, according to Pascal Menezes, CTO of MEF.

The standard will contain definitions for a number of SD-WAN services and service attributes. These include SD-WAN user network interface (UNI), SD-WAN edge, SD-WAN underlay connectivity service (UCS), and tunnel virtual connection (TVC), as well as definitions of functionalities like centralized policy and orchestration.

UNI is something that MEF defines for any service, which Santitoro defined as “the demarcation between the responsibility of the service provider to a subscriber.” So, basically determining who between the user and provider is responsible for the service, and at what point.

SD-WAN edge is “the functionality that could be either delivered by a physical appliance or a virtual appliance that creates the SD-WAN service” said Santitoro, adding that currently this term has a lot of different names in the market such as SD-WAN edge CPE or SD-WAN edge hardware.

“We just say SD-WAN edge because it’s a function, and it’s up to the technology providers to determine: do they want to implement that as a piece of hardware like a customer premises equipment? Or do they want to implement it as a virtual network function, which runs in software and then you can run it on any type of generic compute platform,” said Santitoro.

SD-WAN UCS refers to the requirements for deploying an over-the-top SD-WAN service so it can run over any service providers’ underlay network. This could be running over internet access from cable providers or modems, DSL providers or modems, internet over LTE, or over an LTE modem.

“That’s a really integral part of SD-WAN because you have to connect the SD-WAN edge up to those services to be able to run SD-WAN services over the top of those broadband services as well private services like carrier Ethernet services or MPLS, VPNs, things like that,” said Santitoro.

And TVC refers to the requirements for an overlay network that an SD-WAN provider builds to connect each of the SD-WAN edges that make up the service.

MEF’s work with SD-WAN is far from over. As previously noted, the full standard for the SD-WAN service should be published in July following board approval.

Then later in 2019, MEF will also release an SD-WAN service certification. This certification will be used to test, verify, and certify SD-WAN services from vendors and service providers. MEF CTO Pascal Menezes referred to this as “a key benefit because it gives users confidence that a service meets a fundamental set of requirements.”

One thing that the standards and service definitions will help to enable, according to Menezes, is the inclusion of these SD-WAN services in its standardized lifecycle service orchestration (LSO) reference architecture, “thereby advancing the efforts to orchestrate MEF 3.0 services across providers” through common service attributes, Menezes said, adding that this will help stakeholders to operationalize SD-WAN into a service that is sellable.

The group is working on a security-as-a-service specification for SD-WAN, led by a number of large security vendors. This will be used as a foundation for adding security postures on top of SD-WAN as policy. This comes as security has become top of mind for both SD-WAN vendors and end-users.

MEF has also been working on intent-based networking and building out use cases for that technology. The group plans to have SD-WAN as one of the first use cases, using intent-based networking to define different natural languages for different company personas (such as defining different metrics for IT managers versus business managers).

Long term it intends to determine the framework for applying SD-WAN telemetry data to big data lakes and applying artificial intelligence and machine learning. “That incubation is going to be further out [on the timeline],” Menezes said.

The group also has professional certifications within its MEF tool kit, for which it released an SDN/NFV exam for IT professionals. It has already begun the process of adding SD-WAN content into that exam.