The benefits of software-defined wide area networks (SD-WAN) have many organizations interested in adopting it, but the implementation process can seem daunting. Organizations can use the following seven-step process as a guide to deploying a successful SD-WAN implementation.

Step 1. Gather Requirements

Gathering requirements is always the first step in implementing an SD-WAN architecture.

Compared to MPLS WANs, organizations often cite cost reduction as a key requirement, but SD-WAN technology doesn’t always provide significant cost benefits. Instead, network teams should look to improve the network’s resilience to failures or enhance network security to meet the needs of employees who work anywhere, anytime.

Other benefits include greater business agility through centralized management or reduced operations and maintenance tasks, allowing employees to focus on strategic initiatives.

Step 2. Determine Site Profiles

Use the functional requirements specification to determine connectivity needs, application traffic, quality of service (QoS), quality of experience, bandwidth, and security. Then, identify a small number of different site types in the network. Minimizing the number of different site types improves consistency across the network, resulting in increased automation, faster troubleshooting, and reduced configuration complexity.

The team can categorize sites into the following categories:

① Offices with video conferencing and SaaS connectivity;
② manufacturing facilities
③Warehouses
④ engineering design facilities or medical radiology centers featuring large files, high bandwidth, and custom applications; and enterprise data centers hosting proprietary applications.
The situation at each site determines the functional requirements for factors such as link bandwidth, failover circuits, QoS, security, and monitoring.

Step 3. Select a Proof-of-Concept Site

Identify the proof-of-concept (POC) site. Select a few of the most important site types for the POC. Once these sites have been identified, the next step is to characterize the circuits for these sites so that the appropriate test circuits can be ordered. Lead times for procuring circuits are typically long, so teams should order circuits for the sites as soon as they know which links to order.

Thoroughly evaluate the carrier architecture, as some vendors’ network infrastructures are severely overprovisioned, resulting in high packet loss rates. Note that even small levels of packet loss can result in significant degradation of application performance. Incorporate packet loss measurement and independent measurement mechanisms into the service level agreement with the carrier.

Step 4. Evaluate the Product

Begin a written evaluation of potential products, reference industry resources of potential vendors, and begin to develop selection criteria. The market is changing rapidly and new product features are released regularly. Competition is fierce, but it is expected that features will be comparable across vendors with some proprietary differences. Features such as Secure Access Service Edge are becoming more prevalent.

Keep in mind that the protocols used by SD-WAN are proprietary and there is no interoperability between products from different vendors.

Step 5. Compare DIY vs. Managed Services

Next, determine the types of offerings available: DIY, co-managed with a managed service provider, or fully outsourced to an MSP The choice depends on the resources the team can mobilize for assessment and implementation. For example, global organizations may find it useful to work with an MSP that already has established relationships with foreign ISPs.

Finding an MSP that is familiar with SD-WAN services may work in its favor, as it can bring experienced people, processes, and technology to the table. These resources can simplify the assessment and SD-WAN implementation, making it worthwhile.

Step 6. Testing the Proof of Concept

Begin the actual evaluation of the POC in the lab. This step can be done while waiting for the circuit and can cover as many products as needed, but the network team should limit it to the first two or three candidates. Ensure that performance is evaluated using traffic generators and monitoring capabilities.

Does the policy mechanism provide the required functionality? How easy is the zero-touch provisioning (ZTP) deployment to use? Does the traffic processing policy apply to the traffic mix?How does the SD-WAN interface work with non-transition sites? What visibility does the monitoring system provide? Are security measures effective? Create failure scenarios to evaluate network management alerts and troubleshooting mechanisms.

It can be tempting to create partial or sample policies for testing purposes, but ultimately it may not pay off. It is better to focus on a thought process that identifies all elements of the production strategy so that the team understands the product, its limitations, its capabilities, and whether it is achieving its goals.

During this step, the product can be used without affecting the production application, so be as thorough as possible. Run evaluation tests using the product’s automated system. If possible, also create tests on the production network. This is where an experienced SD-WAN MSP comes in. This step should result in the identification of potential grantees.

Step 7. Determine the SD-WAN model

Determine the appropriate deployment model. Vendors either provide a preferred model or offer customers a choice. Will hardware be required at each site, or will a virtual implementation requiring VM hosts be used?Will ZTP be able to be shipped directly to each site, or will it need to be staged somewhere? How will the team validate the circuit before delivering it to production?

Use the deployment model to scale the POC from the lab to a low-risk production site. If successful, the deployment continues to other POC sites.

This step validates the implementation and deployment model in the production environment. There should be no surprises, except for the discovery of one or two forgotten applications. At least one of each type of critical production site is included in this step to verify that the product meets the most stringent requirements.

These steps can feel laborious, but a thorough approach will make the transition to production implementation much smoother. If you would like to learn more, please contact us at https://www.ogcloud.net/sdWan