MPLS vs SD-WAN: A Comparison for Enterprise WANs

April 15, 2026·3 min read·441 words

MPLS vs SD-WAN: The Major WAN Transition

Since 2017, multi-site enterprises have been migrating from MPLS to SD-WAN on a large scale. The SD-WAN/MPLS ratio in new WAN deployments rose from 15% (2022) to 60% (2026). This migration is driven by 3 factors: cost (MPLS at €800/month vs Internet fiber at €60/month), agility (a new site in 1 week with SD-WAN vs 3 months with MPLS), and cloud connectivity (native SD-WAN optimization for SaaS/IaaS).

MPLS: Benefits and Limitations

Benefits of MPLS

Guaranteed SLA: intra-country latency <30ms, jitter <5ms, packet loss <0.1%, and 99.99% availability.
Security: carrier-operated private network with isolated traffic.
End-to-end QoS: the carrier honors DSCP classes.
Maturity: proven technology with a 25-year track record.

Limitations of MPLS

Cost: 5-10× more expensive than Internet connectivity. A 100 Mbps MPLS link costs ~€800/month vs ~€60/month for 100 Mbps fiber.
Deployment lead times: 3-6 months for a new site.
Limited agility: bandwidth changes take weeks.
Direct cloud access: not optimized, as SaaS traffic is backhauled to headquarters before being sent onward.

SD-WAN: Benefits and Limitations

Benefits of SD-WAN

5-10× lower cost: Internet fiber with optional 4G/5G backup.
Agility: deploy a new site in 1 week (hardware delivery + zero-touch configuration).
Application visibility: 5,000+ applications identified through DPI.
Multi-cloud: direct optimization for AWS, Azure, GCP, and Office 365.
Integrated security (Fortinet) or cloud-delivered SASE (Palo Alto Prisma, Zscaler).

Limitations of SD-WAN

Internet connectivity is best-effort, with no strict SLA.
Appliance dependency: a CPE failure disconnects the site.
Initial complexity: orchestration platforms such as vManage and FortiManager require specialized expertise.

5-Year TCO for 50 Sites

MPLS: 50 sites × €800/month × 60 months = €2,400,000. CE hardware: €100K. Total: ~€2.5M.
SD-WAN (Fortinet): hardware for 50× FortiGate 60F = €35K. 5-year UTP licenses = €140K. Internet fiber for 50 sites × €60 × 60 = €180K. Total: ~€355K.
SD-WAN savings: €2.14M over 5 years (-86%).

Hybrid Architecture: MPLS + SD-WAN

In practice, 70% of large enterprises do not replace MPLS with SD-WAN—they deploy SD-WAN alongside it. Critical traffic (voice, ERP) runs over MPLS, while non-critical traffic (web, SaaS, backup) uses SD-WAN over the Internet. This cuts the MPLS bill by a factor of 3-5 by reducing the required MPLS bandwidth.

MPLS → SD-WAN Migration: Standard Plan

Phase 1 (months 1-3): traffic audit, vendor selection (Cisco, Fortinet, Juniper), and architecture design.
Phase 2 (months 4-6): pilot across 5 sites with dual attachment (MPLS + Internet SD-WAN).
Phase 3 (months 7-12): phased rollout at 10 sites/month.
Phase 4 (months 13-18): progressive MPLS reduction (-50% bandwidth) or complete decommissioning.
Typical timeline for 50 sites: 12-18 months.

OPTINOC supports SD-WAN migrations using FortiGate, Cisco Catalyst 8000, and Juniper SRX.