Will Standards Lessen SD-WAN's Growing Pains?

The call for standards creeps into just about every telecom equipment and service category and the SD-WAN market is no different. However, where SD-WAN stands apart is that it's a feature set, not a piece of hardware, so it's harder to pin down what is and isn't SD-WAN, according to Ovum's Brian Washburn.

For a while there, the SD-WAN market felt a little like a crowd of Elvis impersonators. While they all claimed to be the King -- er, provide SD-WAN -- it wasn't always immediately clear if they truly offered an SD-WAN service or were perhaps WAN optimization companies hiding in glittering bell bottoms.

SD-WAN is All Shook-Up
Image courtesy of Pixabay.
Image courtesy of Pixabay.

Both Washburn and Heavy Reading's Sterling Perrin spoke with Light Reading about how MEF has stepped in to create SD-WAN specifications to provide clarity in the market, and how this service definition could impact the SD-WAN market which raked in revenue of "26% quarter over quarter to reach $359 million in the fourth quarter (Q4) of 2018," according to IHS Markit .

Also, Perrin and Washburn discuss whether the Universal Customer Premises Equipment (uCPE) model of delivering SD-WAN is a growth opportunity for the market, or if the economics don't yet add up.

MEF updates SD-WAN standards
In response to the growing SD-WAN market, MEF has released SD-WAN standards to better define the technology as well as SD-WAN's service characteristics and capabilities. The standards were initially announced last October at MEF '18; MEF issued the final draft of its SD-WAN specifications in May, called "SD-WAN Service Attributes and Services (MEF 70)."

"Enterprises want to know what they're getting, and service providers want to sell more by eliminating confusion," MEF CTO Pascal Menezes told Light Reading's Mitch Wagner.

MEF expects to release the final specification in mid-July, and if it takes hold, Perrin says a uniform definition could be useful in expanding SD-WAN adoption by providing clarity and weeding out vendors that claim to provide SD-WAN but offer services that don't measure up to the industry standard.

"I think the impact will be more going forward than up until today," says Perrin, principal analyst of Optical Networking & Transport for Heavy Reading. "The vendor interoperability portion is probably less compelling, but getting to service specs that define 'what is an SD-WAN service? What are the attributes you need?' does get at reducing the complexity of evaluating and deploying SD-WAN. If it takes, it will be helpful in expanding deployment."

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MEF's definition specifies that an SD-WAN service needs to provide visibility into the application layer, control over the application layer that extends to dynamic path selection, analytics tools to "make sure policies are adhered to," and several other features such as routing, security and WAN optimization, explains Brian Washburn, practice leader of Network Transformation & Cloud for Ovum.

Washburn adds that a clearer definition of the SD-WAN technology and service will be important when enterprises decide to switch SD-WAN platforms, service providers will "want to port customers in as standardized a way as possible. If they need to graduate from one [SD-WAN service] to the other, you're not starting all over again."

If an enterprise changes its mind about which SD-WAN platform is the best fit, having that clearer SD-WAN technology definition could make the transition to a different SD-WAN service "fast and painless with a smooth migration," says Washburn. This will become increasingly important as service providers are expanding the number of SD-WAN flavors they offer to meet different customer demands.

MEF will also be offering certifications for SD-WAN features which could give vendors a leg up during RFPs, explains Washburn. At the end of the day, though, Washburn says some companies may not meet all the feature requirements under MEF's SD-WAN definition, but if an enterprise is satisfied with current services, they'll likely continue to work with that vendor regardless of what certifications they have.

Next page: Hey, uCPE, show me the money!

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Roopashree Honnachari 8/22/2019 | 5:46:50 PM
Re: interoperability question I think the physical appliance itself on which the VNF operates will become immaterial in the future...most vendors do want to get away from the hardware business and want their VNF to run on any hardware the customer chooses. Hence, the heightened focus on the uCPE model. However, the cost, orchestration and management complexities of the uCPE approach has hindered the model from gaining much traction. I don't know if you meant to ask if SD-WAN VNFs from different vendors will be able to interoperate in the future....like a VMware-VeloCloud SD-WAN VNF interoperable with Cisco SD-WAN.  That will be something!
Phil Harvey 7/15/2019 | 2:52:08 PM
Re: interoperability question Thanks, Dan. That helps clear it up.

We'll change "and address the need for vendor interoperability" to "as well as SD-WAN's service characteristics and capabilities" in the fifth graf. 

DanPittPaloAlto 7/15/2019 | 2:42:23 PM
Re: interoperability question Phil,

As Stan explains below, the standardization applies looking upward from the SD-WAN control point toward the applications or OSS/BSS, not the interactions between the control point and the edges. These interactions have been vendor-specific and we have not seen the market demand to standardize these. If the edges are some sort of programmable uCPE then it's likely a swap of one vendor's SD-WAN for another's can be effected through rebooting of VNFs in the uCPE.


ralphsan2 7/15/2019 | 12:15:58 PM
Re: MEF SD-WAN Standard Hi Kelsey,

The new MEF 70 SD-WAN service standard addresses 3 key areas:
  1. Defines the baseline characteristics for a service to be called an SD-WAN service (MEF 3.0 SD-WAN service), e.g., OTT, IP-based, application aware, operates over any service provider's underlay WAN, operates over multiple, different types of underlay WANs, etc.
  2. Standardizes terminology for SD-WAN service components: SD-WAN Edge, SD-WAN UNI, Tunnel Virtual Connections, Underlay Connectivity Services (underlay WAN services), etc.
  3. Defines Application classification criteria and policy definitions to determine what actions are performed for different Application flows on a classification match.

The above items address issues that buyers of SD-WAN services (and products) face as they evaluate different service (or product) offerings.  The standard defines the fundamental characteristics of an SD-WAN service and enables buyers and sellers to use a standard vernacular to more effectively communicate the service components & functionality and define application policies.

The MEF 70 standard is just the begining of SD-WAN standardization with additional work in progress at MEF to define additional SD-WAN service characteristics and capabilities (including security aspects) and the LSO APIs to plug into all aspects of the service from Service Orchestrators to Customer Portals.

Vendor interop is not a focus of the standard.  The above items are far more important to standardize to accelerate SD-WAN service growth and help customers make more informed purchasing decisions.

... Ralph Santitoro

Kelsey Ziser 7/15/2019 | 9:54:09 AM
Re: MEF SD-WAN Standard Hi Stan,

You mentioned that "MEF is not creating SD-WAN protocols for vendor equipment interoperability standards" but MEF is addressing issues customers face by using multiple SD-WAN vendors, correct? Carol touched on that last year: https://www.lightreading.com/carrier-sdn/sd-wan/mef-touts-multivendor-sd-wan-and-more/d/d-id/743511 
Phil Harvey 7/12/2019 | 5:43:52 PM
interoperability question Hi Stan,

More of a reading comprehension question on my part -- The MEF is just defining the service and not specifying how the service should be built, but what it should do -- is that right? 

Second question -- if vendor A and vendor B built gear that delivered the same service, as defined by the MEF, is it possible that gear from vendor A could be swapped out with gear from vendor B with minimal fuss, in the event that the enterprise suddenly wanted to change vendors?

I'm always curious about how much flexibility companies really have when they change their minds about stuff. Not nearly as much as consumers, but probably a lot more than they used to.


stanMEF 7/12/2019 | 5:03:24 PM
MEF SD-WAN Standard Hi, Kelsey.

For your Readers...The draft SD-WAN Service Attributes and Services standard can be downloaded here:  https://www.mef.net/Assets/Draft-Standards/MEF_70_Draft_(R1).pdf

What's in the Standard?

The standard describes requirements for an application-aware, over-the-top WAN connectivity service that uses policies to determine how application flows are directed over multiple underlay networks irrespective of the underlay technologies or service providers who deliver them.

We cover key concepts and definitions like an SD-WAN UNI, the SD-WAN Edge, SD-WAN Tunnel Virtual Connections, and Underlay Connectivity Services. We also define service attributes that describe the externally visible behavior of an SD-WAN service as experienced by the subscriber as well as the rules and policies associated with how traffic is handled. Check out the document for this and more.

What's Not in the Standard?

Just to clarify, MEF is not creating SD-WAN protocols for vendor equipment interoperability standards. We are focused on defining a SD-WAN service with its attributes and policies.

What's Next for Standardization?

The next phase of standardization - MEF 70.1 - will cover things like complex service attributes related to application business importance and prioritization, underlay network characteristics, and connectivity to private/public cloud services. 

Also, stay tuned for more on MEF 3.0 SD-WAN certification.


Stan, MEF

prayson.pate 7/12/2019 | 1:41:28 PM
Re: Time to move past appliances Hi Kelsey,

We are seeing enterprises move to uCPE and virtualized SD-WAN for both economic and strategic reasons.

One recent example is a large enterprise with hundreds of sites worldwide.

They were experiencing severe network problems over the past few years, and were looking for a new way to manage connectivity.

Key requirements were:
  • Secure connectivity to differently sized locations
  • Open, vendor agnostic solution enabling choice of uCPE hardware
  • Easy deployment and management
  • Integration with existing automation tools
  • Ability to host a wide variety of non-networking applications
  • Cost savings of more than 20%

We are now working with our partners to deploy this application.

It is a great example of cloud-centric technology powering innovation - and solving real-world problems.

Kelsey Ziser 7/12/2019 | 1:33:00 PM
Re: Time to move past appliances Excellent points, Prayson, thanks! What I heard from the analysts and have heard from some SPs is that the economics of uCPE are still tricky. Any thoughts on why it makes sense for enterprises to move in thei direction from an economic standpoint?
prayson.pate 7/12/2019 | 1:21:21 PM
Time to move past appliances Hey Kelsey - thanks for the interesting article.

The section "Hey, uCPE, show me the money!" on page 2 spends some time focusing on the difficulty of virtualized SD-WAN for enterprises.

But the penultimate paragraph highlights a huge benefit for enterpises: risk mitigation in the face of unknowns.

With virtualized SD-WAN running on uCPE with a hosting layer, enterprises can experiment with different combinations of SD-WAN and firewalls, without having to change the hardware. This can even be done at a later date if one of the virtualized functions fails to meet expectations.

The days of closed appliances and bare metal SD-WAN is coming to an end. It's time for enterprises to embrace a cloud-centric approach. Innovative enterprises are doing this today.

Prayson Pate
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