SD-WAN – what’s good, what’s not and what to look out for
Software defined wide area networks – or SD-WANs – are coming to a network near you … and soon, writes Manish Aggarwal, the director of technology at Aricent.
Figures suggest the market was worth US$444 million in 2017. Growth has been rapid. IDC estimates the SD-WAN infrastructure and services revenues market is enjoying nearly 70% CAGR and that it will be worth US$8.05 billion by 2021. Understandably, there is much interest from service providers and enterprises alike, not least because of the benefits in terms of agility, ease of management (compared with WANs) and cost-effectiveness.
Since arriving on the scene, SD-WANs have provided a much-needed upgrade for traditional WANs. Software defined networking is not new, but significant advances in orchestration technologies in recent years have increased the level of agility and flexibility deploying these solutions. Applying this approach to the WAN has meant bringing more agility and efficiencies in terms of service deployment, which has in turn meant businesses are better able to up their agility to compete in a digitally-driven world.
The art of the possible
Enter SD-WAN. Highly efficient, significantly lower cost, quickly deployable and easily configurable, SD-WAN solutions can scale to meet the diverse enterprise business needs. It is no wonder they are becoming the de facto industry standard.
There are a number of features that include: zero-touch (thin provisioning), end-to-end service orchestration across branch offices and data centres, hybrid cloud options, built-in analytics and monitoring with machine learning (ML) driven assurance, application classifiers and optimizers and end-to-end security management. The list goes on. Service providers can roll out new services, operate efficiently, deliver high customer satisfaction and improve the customer experience thanks to these features. To paraphrase a political aphorism, SD-WAN could be described as the art of the possible.
Or, does the computer say no?
Why is it that the reality is sometimes a little different? One of the foremost advantages of the SD approach is the agility it confers to service providers and enterprises. However, when both find themselves locked out of all but the most limited set of use cases, or indeed locked into using certain vendors, it is time to look more closely at the deal that is actually on the table.
The acceleration of high-availability telecoms and cloud infrastructure has enabled highly reliable and scalable networking – remember, the art of the possible, but like any new technology trend, there are selection and implementation pitfalls to be avoided. Here are five questions to consider when choosing a SD-WAN solution.
- How proprietary is too proprietary?
SD-WAN should be about opening doors – enabling new services, optimising a network environment to match a customer’s needs or delivering better quality outputs more efficiently than before. The majority of SD-WAN applications operate through proprietary interfaces, which can result in vendor lock-in. Consider open plan alternatives or investing in a master orchestrator that will operate multiple vendor components in the overall ecosystem through standard protocols and application programme interfaces (APIs). This way, service providers not only ensure they are not locked into any specific vendors, they are also not limited in the set of use cases they can deploy.
- Are you swapping one rigid, monolithic system for another?
Big enterprises with multiple branch-office implementations and use cases require different security, routing and rule-based policies. Many SD-WAN solutions currently available are hardened to specific use cases and typically includes different functional components embedded as single monolithic software VNF or single appliance. Managing different SD-WANs heightens the challenge of getting to the desired outcome, whether that is flexibly supporting diverse use cases or correctly balancing policy configurations. Consider an orchestrator that has configurable work flows and open APIs to southbound VNFs that can be easily integrated into the end-to-end solution.
- How easy is it to scale and adopt new solutions?
Interoperability with legacy systems and incremental migration of solutions to all enterprises is an approach CSPs favour. It minimises the capex burden and improves solution stability. Some enterprises resist multiple vendor solutions altogether to avoid complexity. It should not be hard to adopt new solutions with SD-WAN. This can hardly be stressed enough. Solutions should support hybrid WAN management scenarios, flexibility and scalability without disturbing the existing ecosystem. Also, the SDWAN solution should be flexible enough to onboard new virtual network functions other than core SD-WAN functionality and depending on the use-case, CSPs or enterprise users should be able to easily create an end-to-end service through standard service chaining process from a centralised portal.
- How available are different WAN transport technologies?
Single WAN transport technologies cannot address all the business requirements as the needs of each branch office differs. The availability of WAN transport will determine the right choice. An SD-WAN solution must support on-boarding of multiple WAN transport technologies like MPLS, broadband, LTE and others to meet the needs of the different branch locations of enterprises. Depending on the enterprise, location or application requirements, the solution should be able to offer the reliability and performance of MPLS or the scalability and affordability of less expensive link options like broadband and LTE.
- What’s the deal with branch office security?
With branch offices working independently of the enterprise datacentre, branch-office networks are prone to security breaches by connecting to the public networks directly. Service providers need to use best-in-class physical and virtual forms of security functions to strengthen network security at branch offices. Any SD-WAN solution should include comprehensive security functions like secured encrypted tunnels across all end points, stateful and application firewalls with policy-based filtering, denial of service (DOS) prevention and others to ensure robust and safe functionality. In the absence of all security functionality, solution should be able to add third-party security virtualised functions through service chaining.
Enterprises are right to welcome the advent of SD-WAN. Its ecosystem of infrastructure and services will ultimately enable them to innovate agile services and explore new revenue opportunities. Even though the future of SD-WAN is bright and it could be called the art of the possible, it most certainly is not a case of anything goes. Organisations who simultaneously want flexibility and cost-effectiveness need to fully explore the potential of hidden management complexity and the potential of vendor lock-in.