MEF's Universal SD-WAN Edge: Now is the time

The MEF's work on a universal SD-WAN edge standard is good for equipment vendors and service providers. But does it go far enough?

Faisal Khan, Network Operator Technology Planning Dept.

April 20, 2022

4 Min Read
MEF's Universal SD-WAN Edge: Now is the time

When I wrote my last article for Light Reading in 2019, I covered some of the interoperability challenges between different SD-WAN vendors on the data and control plane layers. The main worry back then was that there was not enough going on in the industry to standardize this interoperability. But in 2022, things have changed for the better.

The recent initiative of MEF to standardize a universal SD-WAN edge (still a working draft – W119) with a multi-vendor interoperable data, control and management plane for SD-WAN is indeed a positive move. This is the first industry initiative on this subject.

MEF expects the public draft standard to be ready in the second half of 2022. Meanwhile, I talked to the standard editors – Mr. Neil Danilowicz (Versa Networks) and Mr. Michael Bencheck (MEF). They were kind enough to provide some preliminary details on the work, courtesy of MEF.

Here is my take on the potential of the standard and what it means to a service provider and an SD-WAN vendor; nevertheless, I also present my opinion on the slight room for enhancements in the goals of the standard.

The standard is around a “universal” SD-WAN edge device, which is a device that can communicate with any vendor’s SD-WAN edge, provided that the vendor uses a control and data plane defined as per the future standard MEF 119. Therefore, this standard enables vendor interoperability at the edge.

Interoperable SD-WAN solutions do not exist today. Consider one of the significant use cases where a service provider wants to provide enterprises access to services in the data center or the cloud. With the situation today, a service provider builds islands of SD-WAN systems. For each vendor, it places a dedicated SD-WAN edge device in the data center because a standardized method of interoperability does not exist.

But very soon, the universal SD-WAN edge at the data center will be able to facilitate any vendor to communicate with this universal edge device using a common standard protocol. This universal SD-WAN edge may come from either an existing vendor or a new one.

This will reduce the amount of hardware needed in the data center. Also, it will make the data center less complex because managing hardware with the same configuration is much easier using standard management API.

Figure 1: For a larger version of this graphic, click here. (Source: MEF) For a larger version of this graphic, click here.
(Source: MEF)

What USWE means to service providers and SD-WAN vendors

While service providers love selling managed SD-WAN services, they are obliged to build capex-intensive inventory in the data centers. They need to procure dedicated data center hardware for each vendor. A unified USWE reduces the need for a lot of hardware in the data center. A standard management API further simplifies the configuration and provisioning of services, reducing operational expenses.

The SD-WAN vendors that comply with the standards can benefit in other ways: A service provider that finds easily deployable multi-vendor solutions can always be open to adding more SD-WAN vendors.

Even while adhering to the standard, the vendors will be able to use their proprietary SD-WAN data and control plane in parallel for some of the services, in addition to the standardized data/control plane. This means that any SD-WAN vendor can keep its secret sauce and thus provide differentiating features, which standard MEF services such as MEF 70.1 do not cover.

This is where I think the standard can be enhanced. While the standard is the first step in eliminating the need for dedicated SD-WAN edge devices at the data center, the branch-to-branch connectivity will still require hardware from the same SD-WAN vendor in both branches. Such kind of multi-vendor interop between the branches is not covered in the standard, at least in its first release, but may be covered in the future once issues around provisioning are worked out, from what I've been told.

As a service provider, some of my use cases require branch-to-branch mesh connectivity. I would like to mix and match vendors here instead of depending on one vendor.

Think about it: if the control and data plane is standardized in SD-WAN, why restrict it only to the universal SD-WAN edge in the data center? The universal SD-WAN edge is a function that can be ported to the branch as well. This will be the ultimate interoperability desired in the SD-WAN today.

Regardless, the universal SD-WAN edge is still a big step and the right step by MEF. This interoperability has been needed for a while. It will reduce the operations costs as well as capital costs. Instead of buying multiple vendors' products to put in the data center for every enterprise variation, service providers will soon have a unified SD-WAN edge enabling consistent management and provisioning, and expediting the time to market the services.

– Faisal Khan, Telco Cloud blogger, service provider employee and Light Reading contributor

[Editor's note: On April 22, the original title of this article, "The MEF's Universal SD-WAN Edge: Better Late Than Never," was changed at the author's (and probably the MEF's) request.]

About the Author(s)

Faisal Khan

Network Operator Technology Planning Dept.

Faisal Khan writes on his blog at  on issues facing service providers on subjects related to SDN, NFV, Virtualization, IP and Optics. He has rich experience, working with multiple service providers and vendors in Middle East and Africa region. Currently, he works for a mobile operator Mobily in Saudi Arabia in technology planning department.  The views expressed in this blog are his own and does not represent the views of his employer.

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