Summary:
SD-WAN deployment doesn’t eliminate WAN complexity; it changes it. Enterprises succeed when they plan for real-world conditions. The key lessons are clear: most deployments end in a hybrid WAN, the underlay network quality still drives performance, DIY creates hidden costs, monitoring is essential, and managed services make SD-WAN sustainable.
Vendors pitched SD-WAN deployment as the solution to WAN complexity. They promised lower costs, centralized control, and cloud agility that MPLS could never match. The story sounded simple: buy a few appliances, configure the software, and the WAN problem disappears.
After hundreds of enterprise SD-WAN deployments, we have found the reality looks different. SD-WAN works, but not in the easy way sales pitches suggested. It doesn’t remove complexity; it changes it.
The technology still provides great value. It offers flexibility, agility, and better cloud performance. However, this is true only when IT leaders plan for the real situations they face.
Here are five lessons that show up in almost every SD-WAN deployment.
Lesson 1: Hybrid WAN is the rule, not the exception
Many believe SD-WAN deployment makes MPLS obsolete. In reality, the two work best together.
Some workloads — trading systems, healthcare imaging, or manufacturing controls — can’t risk packet loss or latency. MPLS still provides the stable, predictable performance those apps need. SD-WAN delivers agility and lower costs for everything else.
What actually happens in deployments:
- Enterprises that cut MPLS often bring it back later.
- SD-WAN devices pair with MPLS for critical apps, while internet links carry general traffic.
- Most rollouts end in a hybrid WAN model.
Enterprises that succeed accept hybrid as the default. They treat SD-WAN as the scaling layer and MPLS as the safety net. This mindset creates smoother rollouts, fewer disruptions, and stronger ROI.
👉 Deployment insight: Don’t design for a clean break. Design for coexistence.
Lesson 2: The underlay still matters
Another myth of SD-WAN deployment is that the overlay makes the underlay irrelevant. While SD-WAN can reroute traffic and add resilience, it can’t turn a weak ISP into a strong one.
Performance still depends on the quality of the underlay. Enterprises see this during global rollouts:
- In North America and Western Europe, links usually perform well.
- In Southeast Asia, Africa, or Latin America, inconsistent ISPs cause issues.
- Carrier diversity and redundancy remain essential.
Too many deployments fail because teams treated the underlay like a commodity. The best deployments choose the right carriers, design redundancy into sites, and set performance expectations by region.
Enterprises that plan this way get consistent, measurable performance. Those that don’t end up firefighting outages and explaining to executives why the “new WAN” doesn’t feel stable.
👉 Deployment insight: the overlay is powerful, but the underlay sets the baseline.
Lesson 3: DIY creates hidden costs
At first, DIY SD-WAN deployment looks attractive with no managed service fees, cheaper circuits, and more control. In practice, those savings often disappear.
Hidden costs show up fast:
- Engineering teams spend hours turning up new sites.
- Outages trigger multi-party calls between carriers, vendors, and IT.
- Added features like security or monitoring increase license costs.
- The help desk absorbs the burden without a managed layer.
One IT leader called it “death by a thousand tickets.” Each issue may be small, but together they drain resources and morale.
DIY doesn’t fail because SD-WAN is flawed. It fails when IT teams underestimate the operational load. A managed SD-WAN deployment does not remove complexity. Instead, it makes it more predictable, allowing IT teams to focus on strategy.
Most enterprises choose between three deployment options – DIY, managed or co-managed:
DIY puts everything on the IT team.
- DIY put everything on the IT team.
- Managed transfers operations to a provider.
- Co-managed splits responsibilities, giving IT visibility and control while the provider handles day-to-day operations.
👉 Deployment insight: DIY works for some, but managed models deliver better results at scale.
Lesson 4: Monitoring isn’t optional
Many assume SD-WAN dashboards give enough visibility. They don’t. Without real-time monitoring, IT works reactively instead of proactively.
The common pattern:
- Dashboards show circuits as “up”.
- Users complain about call drops or lag.
- IT spends days chasing issues across ISPs.
Strong deployments invest in monitoring that unifies MPLS and SD-WAN into one view. They measure latency, jitter, and packet loss. Some add AI-driven tools that spot problems before users notice.
Monitoring doesn’t just protect performance. It builds trust. Business leaders want proof that the WAN delivers consistent results. Monitoring provides that proof.
👉 Deployment insight: Without monitoring, SD-WAN stays reactive. With monitoring, it becomes strategic.
Lesson 5: Managed beats unmanaged
The most consistent SD-WAN deployments share one trait: they have management. Enterprises usually decide between managed or co-managed models. Both reduce the burden on IT compared to DIY, but co-managed gives IT leaders more direct involvement while still offloading daily tasks to the provider.
Managed SD-WAN simplifies operations by:
- Monitoring and reporting across carriers.
- Handling escalations so IT doesn’t have to.
- Supporting compliance for lawful intercept, retention, and emergency services.
- Delivering the same processes and SLAs worldwide.
Large enterprises with dozens or hundreds of sites rarely keep up with DIY. Managed services bring scale and predictability. They don’t make SD-WAN effortless, but they make it sustainable.
👉 Deployment insight: Managed doesn’t make SD-WAN easier, but it makes it viable long term.
DIY vs managed SD-WAN deployment
| Factor | DIY SD-WAN | Managed SD-WAN |
| Operational load | High — IT handles troubleshooting, site turn-ups, vendor wrangling | Low — provider consolidates and manages |
| Cost control | Unpredictable — licensing creep, hidden labor costs | Predictable — SLA-backed, bundled services |
| Monitoring | Fragmented, often reactive | Centralized, real-time service assurance |
| Compliance | Enterprise carries the risk | Provider supports regional obligations |
| Scalability | Slower — each site is custom | Faster — standardized rollout model |
The real lessons of SD-WAN deployment
SD-WAN deployment brings value, but it isn’t a shortcut. It shifts complexity instead of removing it — and that works when enterprises plan for it.
The lessons are clear:
- Hybrid WAN is the practical model.
- The underlay sets performance.
- DIY adds hidden costs.
- Monitoring moves SD-WAN from reactive to strategic.
- Managed services make deployment sustainable.
SD-WAN isn’t the end of the WAN. It’s the next stage of its evolution. Enterprises that design for its realities gain the agility, performance, and resilience they expect — without the regret of treating it like a quick fix.
Talk to BCM One about making SD-WAN work the way it should. Our managed approach turns complexity into control — giving your enterprise the agility, performance, and resilience you need.
Frequently asked questions about SD-WAN deployment
What is the biggest challenge in SD-WAN deployment?
The main challenge is underestimating complexity. Many expect SD-WAN to replace MPLS overnight, but most deployments end as hybrid WAN. Underlay quality, ISP diversity, and monitoring matter as much as the overlay.
How long does an enterprise SD-WAN deployment take?
It depends on size and geography. A mid-sized enterprise may finish in 6 to 12 months. Global deployments take longer due to carrier coordination and compliance.
Should enterprises manage SD-WAN deployment or use a provider?
DIY gives control but creates heavy workloads. Managed services provide scale, consistency, and predictability. Most large enterprises now choose managed models.
Does SD-WAN deployment eliminate MPLS?
No. MPLS still supports latency-sensitive and mission-critical apps. Most enterprises adopt hybrid WAN, combining MPLS with SD-WAN.
What’s the ROI of SD-WAN deployment?
Savings come from reducing MPLS use, centralizing control, and optimizing internet links. ROI varies, but most enterprises report gains in agility, user experience, and cloud performance.
