SD-WAN vs NaaS: what is the difference and how do they relate?

SD-WAN (software-defined wide area network) is a technology that centrally controls how traffic is routed across several links. NaaS (network as a service) is a consumption model in which you pay for network capability from a provider. One describes how it works, the other how you buy it, so they often appear together.

What is SD-WAN?

SD-WAN separates the control of a wide area network from the devices that forward traffic. A central controller sets policy, and edge devices at sites choose paths across links such as broadband, mobile data and private circuits, based on that policy. Typical goals are using cheaper links well, keeping applications fast and making site setup quicker.

NIST SP 800-215, the guide to secure enterprise networks, lists SD-WAN among the technologies that matter as organizations spread across multiple cloud services, data centres and microservices based applications. The same guide covers related ideas such as secure access service edge, zero trust network access and microsegmentation.

What is NaaS?

NaaS has no standards body definition, so providers use it loosely. The common meaning: instead of buying and running routers, switches and links, you subscribe to a network service delivered and operated by a provider, billed by usage or subscription. The provider may run SD-WAN, wireless, data centre connectivity and security features under one contract.

Because the term is a marketing one, check the contract for what it actually includes: who owns the hardware, who operates it, what service levels apply and who is responsible for security controls.

How do they differ?

So "SD-WAN vs NaaS" is not a real either or. A better question is: do we run SD-WAN ourselves, or buy it as part of a managed service?

A constructed example

A regional retailer has 120 stores and a small network team. Option one is to buy SD-WAN appliances, configure policies and operate the system with staff. Option two is a NaaS contract where a provider supplies the devices, manages the controller and offers a monthly fee per site.

Option one gives more control and needs skilled people. Option two reduces effort and shifts operations to the provider, but you now depend on the provider's change speed, staff access and security. In both options the retailer still decides which store systems may talk to which, and who can log in to the controller.

What are the security questions?

• Who can change policy? A controller that sets rules for every site is a high value target. Ask about strong authentication, role separation and audit logs.
• Where is traffic inspected? Local breakout to the internet is efficient, but needs security checks at the site or in a cloud service.
• How are keys handled? Site to site tunnels depend on key management, and so does recovery after a lost device.
• What does the provider see? In a managed service the provider's staff and tools touch your traffic and configuration.
• How is an exit handled? Check how you retrieve configuration and move to another provider.
• Is there segmentation inside sites? The WAN does not remove the need for it. NIST's guidance on zero trust (SP 800-207) argues against implicit trust based on network location.

How to check or apply this

1. Write down which of these you want from a network: control, speed of rollout, cost predictability, security features.
2. Split the decision in two: architecture (SD-WAN or another) and operating model (self run, co-managed or NaaS).
3. Ask each provider for a responsibility table that names who handles each security task.
4. Request audit evidence for the controller, such as access logs and change history.
5. Plan a pilot with three sites, including a failure test.
6. Keep your own copy of policy and inventory.

Quick check

Sources

• NIST SP 800-215, Guide to a Secure Enterprise Network
• NIST SP 800-207, Zero Trust Architecture
• NIST SP 800-41 Rev. 1, Guidelines on Firewalls and Firewall Policy

Last reviewed: 18 October 2026.