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Back in 2015, we referred to hybrid wide area network (WAN) as a heterogeneous hub deployment with a variety of global network connectivity options (MPLS, dedicated internet, broadband, wireless, etc.) Since then, the case for software-defined WANs (SD-WAN) and its huge potential for unlocking a more agile and cost-effective network has been made, as more and more companies are testing their SD-WAN implementations before deployment in order to assure SD-WAN performance, scale and resiliency.
7 key SD-WAN testing considerations
1. Policy Validation
Policy is what determines where dynamic path selection will steer traffic and what level of priority (Quality of Service or QoS) it is given. Ensuring policy adherence is a major challenge and manually validating policies is both labor-intensive and error prone. Testing SD-WAN policies that define a given service will help determine if they are pushed from SD-WAN controller to the CPE/vCPE and/or the provider edge devices.
2. Path Selection
Dynamic path selection is the ability to automatically and selectively route traffic onto one WAN link or another depending on network conditions or traffic characteristics. It is important to test SD-WAN device for both static SLA policy-based routing or dynamic routing based on status of the links/paths, such as congestion, link-failure and a certain level of packet loss.
3. QoS Prioritization
SD-WAN solutions when configured optimally can select from the assortment of private links and public Internet connections. This helps prioritize latency-sensitive traffic (say via MPLS) with guaranteed QoS or offload non-critical traffic or even combine links to approximate MPLS Offloading. Testing allows you to measure QoS (and QoE) with application traffic under real-world conditions across the SD-WAN circuit.
4. Resiliency/Fail-Over
SD-WAN device’s key task is maintaining the highest level of availability for business-critical services. During incidents of network failure, this may be at the expense of non-critical services. Testing is essential for assuring SD-WAN’s failover mechanisms, which reprioritizes services, preempting lower priority services where necessary, and reconnecting critical services via the remaining link(s).
5. Zero-Touch Provisioning
With Zero-touch provisioning, configurations and policies are programmed once and pushed to all branch locations without having to manually program each device individually using a CLI. It reduces human errors and eliminates the need to send specialized IT resources out to branch locations whenever a new application is added, or a policy is changed.
6. Service Chaining
An additional characteristic of SD-WAN is the ability to chain it together with other network services. WAN optimization is often combined with SD-WAN to improve network and application performance. Internet traffic leaving and entering a branch office may be routed across a VPN to a cloud-base security service to strike a balance between performance, security, and cost.
7. Dual Stack Addressing
With rapid deployment of Internet of Things (IoT) devices, there is an increasing demand for unallocated IP address making IPv4 and IPv6 coexistence a reality. Testing SD-WAN connections for IPv4, IPv6 and/or dual stack addressing will provide SD-WAN vendors with a unique advantage in large-scale, enterprise-wide deployments.
7 Test Requirements for SD-WAN
MEF introduced the industry’s first SD-WAN service definition standard in 2019.
MEF introduced the industry’s first SD-WAN service definition standard in 2019. MEF 70 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.
MEF 90 further defines the test requirements for MEF 70 conformance. Spirent has developed a test plan with a well-designed test methodology which fully conforms to the MEF 90 SD-WAN service test requirement specification.
The SD-WAN standardization effort is expected to help accelerate SD-WAN market growth while improving overall customer experience with hybrid networking solutions.
Certified SD-WAN Technology Providers and Vendors
As MEF’s Authorized Certified Test Partner, Spirent is helping validate that SD-WAN services and products conform to the global MEF 70 standard. Congratulations to both SD-WAN technology vendor and service providers teams that have been awarded MEF 3.0 SD-WAN certifications to date (and more coming soon):
Check MEF Registry for the latest services certifications and technology certifications granted.
Spirent is helping to assure the promise of SD-WAN, from design, development to deployment.More blog series to follow on how to unlock SD-WAN’s potential to become an autonomous, self-managing domain.
This blog was originally published in March 2020 and republished with updates.
