SD-WAN simplifies the management and operation of a WAN by decoupling (separating) the networking hardware from its control mechanism. This concept is similar to how software-defined networking implements virtualization technology to improve data center management and operation.
Having said that, the proprietary nature that many of the current SD-WAN solutions take to manage their network, and more importantly the approach that many enterprises are taking to adopt SD-WAN, open a new set of challenges that I will try to highlight and address in this post.
I will start with a quick recap of the current SD-WAN market.
How big is SD-WAN?
The following diagram provides an estimated market size of the SD-WAN market by 4 leading analyst firms.
The big variation between the different analyst reports can be explained by the differences in the definition of what is SD-WAN. The big numbers comes from a fairly broad definition of the category :
“SD-WAN hardware that includes appliances and routers, SD-WAN software that includes orchestrators, gateways, cloud routers and firewalls, dashboards, management systems among others, and SD-WAN services that includes Service Provider Managed SD-WAN services and Cloud Managed SD-WAN services.”
Gartner seem to have a narrow version of that definition and thus significantly smaller projections than the rest of the analyst firms.
Regardless of that difference Gartner also estimates that the growth of the SD-WAN market will be significant as noted in their report:
By year-end 2023, more than 90% of WAN edge infrastructure refresh initiatives will be based on virtualized customer premises equipment (vCPE) platforms or software-defined WAN (SD-WAN) software/appliances versus traditional routers (up from less than 40% today).” – Gartner
If we look at the total revenue from the SD-WAN vendors we can see that the actual SD-WAN market already crossed the $1B mark in 2018!
The bottom line is that everyone recognizes the fact that SD-WAN market is fairly significant, but the actual size depends on the way you segment the market.
The challenges with existing SD-WAN solutions:
The differences in the definition of SD-WAN is also indicative of the state of SD-WAN solutions, which tend to vary significantly and that leads to the following new set of challenges:
- It’s a jungle out there – the are many kinds of SD-WAN solutions and approaches with little consistency between them.
“Not having a one-size-and-vendor-fit-all solution for network routing in the enterprise WAN will become the new norm, especially as networking moves to all software that can run on commodity and virtualized hardware.” (Source: Adopting a Multi-Vendor SD-WAN Strategy)
- Yet another silo – Limited integration with existing enterprise network. SD-WAN is managed today as an overlay network that is independent of the existing enterprise network. This approach was taken to allow the adoption of new SD-WAN solution without forcing and integration or changes to the current network. The flip side of this approach is that it also makes those new SD-WAN environment yet another silo. The fact that it doesn’t replaces any of the existing network devices but add another layer of devices on top can eventually lead to increase of the overall complexity as pointed out by Gartner:
“Many SD-WAN deployments today haven’t actually replaced traditional routers; they’ve supplemented them for a variety of reasons, including risk aversion and lack of support for legacy T1/E1 interfaces.” (Source: Gartner)
- Done mostly manually – Most of the SD-WAN solutions come with their own, often limited, orchestration and API but most organizations are still managing their SD-WAN network manually. The ZTP process exposes some security vulnerabilities that not all organizations can adopt without customization to fit their own security policy.
- Lock-in – The proprietary nature that many of SD-WAN solutions represent a new degree of lock-in. Lock-in not just on a specific network device but on your entire network! There is already an initiative that strives to counter this vendor-lock, stay tuned for updates from them.
- High Bandwidth Overhead – The flexibility brought by SD-WAN can in some cases come with a significant increase in the network bandwidth utilization as noted in this specific case:
- SD-WAN accounts for about 3X bandwidth increase because all traffic is duplicated and SD-WAN introduces overhead to the packets (Source : SD-WAN DIY, Moving Away from the Cookie Cutter Model). This is an example presented by an enterprise at a panel in the SD-WAN Summit in Paris. 3X increase is not necessarily the normal case as not all deployment will select to duplicate all the traffic and SD-WAN overhead varies between the vendors.
Unlocking your SD-WAN solution with Open Orchestration
A pragmatic approach to address those challenges is by adding an open-orchestration layer that is independent of a specific SD-WAN solution and as such will allow customers to integrate their SD-WAN solution with their existing network, as well as have better control over their entire network as outlined in the diagram below:
By adding an independent orchestration layer on top we can address many of the current challenges by providing:
- Consistent End to End automation of your entire network including the cloud network.
- Allowing full automation of the SD-WAN HQ/Branch connectivity
- Open abstraction will allow minimizing the SD-WAN vendor lock-in
- Adding an Intent based front-end allows to adopt an application driven approach for managing SD-WAN network and integrating it with an organization cloud and DevOps processes.
Unlock your SD-WAN for the future
The reality of SD-WAN as we know it today is expected to go through a major disruption and transformation as cloud-vendors takes a bigger footprint into the corporate private data-center.
In addition to advancement in open-source, generic edge platforms open the market for more open SD-WAN solutions that will be based on open-source and cloud-native stack:
“The long-term strategy is to move to a peer-to-peer edge network to reduce network latency. Augmented reality and edge computing to support applications such as manufacturing reliability and driverless cars require users and applications to be within 5ms transport of each other.”
The move to cloud and open-source will allow the adoption of more application driven networking through DevOps practices, as we have seen in other layers of the infrastructure.
Having an open intent based orchestration on-top of our existing SD-WAN solution will allow organizations to add those new advancement to their current network without continually disrupting their existing operation.
Adding intent based orchestration will also allow those organizations to have a consistent software-driven-network that can be easily managed through application and DevOps processes from the core to the edge.
Taking full control over your network with DIY
Do it yourself (DIY) approach provides the ultimate control and flexibility over your network. According to Gartner Magic Quadrant for WAN Edge Infrastructure report historically more than 60% of deployments In North America, are do-it-yourself (DIY).
Amir Zmora provided an interesting DIY case study by Gregory Cauchie from Carrefour in his post SD-WAN DIY, Moving Away from the Cookie Cutter Model:
“Gregory Cauchie from Carrefour was a surprise to all as they have built a team of experts in networking and SW in order to build their own SD-WAN based network. They are of course using various open source components but at the end of the day, it is a full-blown DIY SD-WAN deployment. Their reasoning for this choice was similar to the one of Interroll, Special needs that also require much more control than what is offered by the existing SD-WAN options on the market today”
Last year we first introduced the Partner Communication case study that took the DIY approach to build their own custom SD-WAN. Another real world example for a DIY use case is presented in the following case study done in collaboration between 6Wind, Advantech, Cloudify and Intel that created IPSEC tunnels to create a backbone mesh connecting thousands of wireless base solution as can be seen in the following diagram.
Having said that, DIY often comes with a high toll in the form of complexity and requires fairly advanced networking skills that most organizations don’t have. This makes the DIY approach applicable only to a small number of fairly large organizations.
Having open orchestration combined with the advancement in open-source frameworks and cloud based networking, reduces the complexity significantly and therefore reduces the barrier to entry for a DIY approach. That will allow a broader number of organization to adopt a DIY approach to manage their cloud and enterprise branch network.
The following network automation code examples provides a useful reference on how you can provision, configure and chain together network services using open orchestration. It provides a good starting point to learn how you can integrate and automate your existing SD-WAN solution or build your own custom SD-WAN.
Final words – The Only Constant is Change
There is no doubt that SD-WAN is expected to grow significantly over the next coming years but it is also very likely that the SD-WAN of tomorrow will look vastly different than the SD-WAN of today and will be more open, application-driven and cloud-native.
The “green field” approach that I’ve seen taken by many enterprises today, seems to underestimate the toll that they are about to pay for building yet another silo that is not integrated with their existing network environment, that is closed, and is not future proof by any means. With that approach I expect that many will fall on the same challenges that led 70% of the initial NFV projects towards failure.
In this post I wanted to suggest that regardless of whether you have taken a existing SD-WAN solution or DIY approach orchestration has an important role. Orchestration can unlock your existing SD-WAN solution by integrating it with the rest of your network. Orchestration can also reduce the barrier to entry if you choose the DIY approach. Most importantly it will provide the degree of flexibility needed to adopt to new advancements in this field and thus be ready for the future; because at the end of the day the only constant is change and that change will always happen sooner than you think.