Summary & Conclusions of SD-WAN sessions at Telecom Council’s TC3 Summit


As noted in an earlier blog post, the 9th annual Telecom Council Carrier Connections (TC3) Summit was held Sept 29th and 30th, 2016 in Mt View, CA.  A second TC3 article on 5G regulation is here.

In his opening remarks, Telecom Council Chairman Derek Kerton stated that telcos have turned to start ups for innovation, rather than expanding their own labs.  He noted that Network Function Virtualization (NFV) and Virtual Network Function (VNF) have the potential to dis-intermediate the supply chain which presents a huge opportunity for networking software start-ups.  It provides telcos with agility and increased speed of deployment by converting traditional network hardware functions into software (e.g. virtual appliances) running on generic compute servers.

One such opportunity not specifically mentioned, but described in TC3 sessions, was Software Defined (SD)-WAN.  It’s intended to be an overlay of existing corporate WANs that offers many benefits to both telcos and their enterprise customers.  We review the two TC3 SD-WAN sessions in this post.  Both took place on September 30, 2016.  The Summary & Conclusions section provides this author’s opinion on this topic.

1.  Spotlight on SD-WAN:

Abstract: SDN is a big telecom trend that builds on the progress made in NFV. That is, essentially, leveraging virtualization constructs to improve the cost, performance, and reliabilit. But SD-WAN is a specific application of SDN that applies mostly to enterprise networks. It is a product that an enterprise can build, or buy from a network operator. SD-WAN provides a layer of abstraction that lets the enterprise build a reliable virtual network across branches (similar to MPLS), but to do so by using cheaper, lower quality wide-area links and commodity hardware. Control in an SD-WAN is shifted to the cloud, either aaS from a network operator, or managed by the IT department of the enterprise. This session will discuss what SD-WAN means for the long-standing partnership between carriers and their largest enterprise customers, and the technology gaps startups can fill.

Panelists: Chris Cavigioli of Intel and Tom Komuro of NTT-Communications

Summary:  SD-WANs have the potential to disrupt the way enterprise WANs are built and managed, according to Chris.  He said the SD-WAN focus is connecting corporate headquarters to branch offices with centralized network management.   There are a lot of start-ups in that space using general purpose hardware with Intel Xeon processors, he said.  A key advantage of SD-WAN was said to be software based network reconfiguration.  It uses “SDN principles” like programmability and abstraction of functions, but not necessarily the classical SDN definitions of separate Control and Data planes with a Centralized SDN controller with global visibility and path selection.

NTT has been working with US based SD-WAN software vendors to evaluate their “platform” solutions, according to Komuro-san. However, they have not yet made a decision on a specific SD-WAN platform, which must be integrated with their existing network.  Some of the new SD-WAN vendor entrants mentioned include: Viptela, Nuage Networks (owned by Nokia), Velo Cloud, Cloud Genix, Versa, and iGlue.

According to Komuro-san, the benefits of SD-WAN:

  • 40 to 80% cost reduction
  • Zero touch provisioning (1 touch for NTT)
  • Simplified, less brittle, better network availability
  • WAN optimization
  • Agility
  • Less Risk (we strongly disagree!)


How SDN technology is taking over the Software Defined WAN or SD-WAN

Graphic courtesy of SDxCentral


Komuro-san said a “game changer” would be to combine SD-WANs with Virtual CPE (vCPE)1, yet he didn’t define what NTT was doing for the latter or why the combination of the two was a “game changer.”

Note 1.  Virtual customer premise equipment (vCPE) is a way to deliver network services such as routing, firewall security and virtual private network connectivity to enterprises by using software rather than dedicated hardware devices. By virtualizing CPE, providers can dramatically simplify and accelerate service delivery, remotely configuring and managing devices and allowing customers to order new services or adjust existing ones on demand.

In closing, Komura-san reiterated that NTT-Communicaitons needs to make a decision on “the SD-WAN platform business.”  He did not provide timing for that decision.

Here’s a reference NTT blog post I found on the web:

In answer to a question from this author, Chris admitted there were no standards for SD-WANs which implies no interoperability, i.e. single vendor solution for a given network provider and no SD-WAN inter-networking.  That’s a big risk when the single vendor is a start-up!  See Conclusions section below for more on this theme.

2. Case Study: Deutsche Telekom and VeloCloud:

Panelists: Sumanth Sathyanarayana of Deutsche Telekom TLABs (Mt View, CA) and Michael Wood of VeloCloud

Summary:  Deutsche Telekom has set-up a SD-WAN test bed between the U.S. and Germany, enabling it to demonstrate simplified orchestration and rapid deployment of industrial networking. Using VeloCloud’s SD-WAN solution, Deutsche Telekom (DT) interconnected its Telekom Innovation Labs’ headquarters in Berlin with its Silicon Valley Innovation Center (SVIC) in Mt View, CA, to prototype an agile, responsive industrial network with minimal cost and management impact to existing private networks.  The use case was remote 3D printing and monitoring between Berlin and Mt View.

VeloCloud’s SD-WAN equipment consists of three software controlled boxes:  Edge, Gateway and Orchestrator.  The SD-WAN solution was said to enable enterprises to support application growth, network agility and simplified branch implementations while delivering optimized access to cloud services, private datacenters and enterprise applications. Global service providers are able to increase revenue, deliver advanced services and increase flexibility by delivering elastic transport, performance for cloud applications, and integrated advanced services all via a zero-touch deployment model.

“Within the first week we had the VeloCloud SD-WAN set up.  The setup and connectivity were very easy since it is a plug and play solution. We also shipped equipment to the other locations and made similar connections in a very short time. VeloCloud gives us agility through programmability, and capabilities such as automatic WAN link discovery and monitoring eliminate having to configure links and branch locations individually.”

According to Sathyanarayana, with a network powered by VeloCloud for this next-generation project in place, Deutsche Telekom Innovation Laboratories in Berlin and Mt View were able to validate SD-WAN architectures and capabilities supporting industrial 3D and robotic automation.

However, no commercial service or business arrangement was announced between DT and VeloCloud.  Michael Wood said that VeloCloud has 130 partner companies, including telcos and system integrators who could provide their SD-WAN solution in Germany.

Another Opinion on SD-WANs:

In a related blog post, Chris Grossner of IHS-Markit wrote:

“SD-WAN vendors are gaining traction. North American service providers continue to enter the market, including CenturyLink, which is using Versa Networks’ solution, and Verizon, which is partnering with Viptela and Cisco.”

Cliff followed that up with a clarifying email to this author:

“SD-WAN, as implemented by most of the vendors is not a replacement for MPLS. It is an overlay on top of MPLS or Broadband services. Essentially an “over the top” play. In the case of a SP offering SD-WAN, they are currently using vendor equipment such as Viptel, Versa, and VeloCloud to provide the service. Perhaps in the future with SDN/NVF vCPE use case this will change.   Many of the solutions SD-WAN solutions allow the use of many different and lower cost link types Broadband(Internet wireline and wireless) along with MPLS. This is the power for the solution allowing a cost reduction for the enterprise.”


A “software defined enterprise WAN” (SD-WAN) is an overlay network with IP-MPLS VPN as the most common underlay network.  A key point that no one seems to talk about is that the software controlled overlay network must interface with the underlay network, especially in the event of failure and recovery/restoration.

Currently, there are no standards and hence no cross network or interoperability of network vendor equipment and/or software.  Each network provider’s SD-WAN is unique to that provider and is often a single vendor solution due to the lack of interoperability standards.

Chris Cavigioli of Intel had suggested ONUG might play a role in specifying SD-WAN interoperability2.  But ONUG is hardly a standards body! It’s an organization of end users pursuing requirements for open networking.

Note 2.  ONUG has an Open SD-WAN Exchange (OSE) initiative, which is an open framework to allow for one vendor SD-WAN solution to directly talk to another vendor SD-WAN solution without reliance on underlying infrastructure and/or protocols. The “Open SD-WAN Exchange use cases address marketplace M&A, business partner connectivity, Cloud/Service Provider network connectivity, technology transition and vendor lock-in mitigation.

FYI, here’s the ONUG white paper on SD-WANs.  It’s hardly a design spec!

Hence, we see SD-WANs being deployed in segments of a carrier’s enterprise WAN network.  There’s a serious concern that without standards or any type of interoperability between different vendor SD-WAN platforms, a service provider would be in a lot of trouble if the start-up they were using for that platform went out of business or their SD-WAN solution was not as robust as advertised or thought.