MPLS (Multiprotocol Label Switching) is often regarded as one of the most elegant service provider networking technologies after TCP/IP itself because it solved several big problems introduced in the late 1990s (and I got to be part of that):
- Traffic Engineering – MPLS allowed carriers to route packets along explicitly defined paths rather than just shortest-path routing, making far more efficient use of backbone links.
- QoS and SLAs – It enabled service providers to guarantee latency, jitter, and loss characteristics, something IP alone couldn’t do easily.
- VPN Services at Scale – MPLS Layer-3 VPNs (RFC 4364) and Layer-2 VPNs revolutionized managed enterprise WANs, replacing Frame Relay and ATM.
- Technology Agnostic – “Multiprotocol” was real: MPLS could carry IPv4, IPv6, Ethernet, ATM, even legacy protocols over a unified backbone.
- Separation of Control and Forwarding – Labels decoupled forwarding decisions from IP lookups, which both simplified hardware design and sped things up.
- Security – there has never been a security breach in any MPLS network (unlike almost every other of the “greatest networking technologies” listed below)
For service providers, this was game-changing. Many argue that without MPLS, the explosion of managed VPNs, large-scale broadband backbones, and cloud interconnects would not have scaled as well.
For Fun and Perspective: Here is my shortlist of “Greatest Networking Technologies”
Here are my rankings of the technologies most often considered the most impactful in networking history, and we can clearly see MPLS in my list:
- TCP/IP
- The foundation of the Internet.
- Universality, scalability, and openness made it the “greatest of all time.”
- Ethernet
- Dominated the LAN, scaled from 10 Mbps to 400 Gbps+, cheap, reliable.
- “Ubiquitous and invisible” — every device speaks it.
- DNS
- The naming system that made the Internet human-usable.
- Without it, the Internet would still be a numbers-only space.
- Wi-Fi (IEEE 802.11)
- Freed networking from wires, exploded consumer Internet use.
- Extended connectivity into homes, coffee shops, airports.
- MPLS
- Revolutionized provider backbones and enterprise WANs.
- Enabled VPNs, traffic engineering, and QoS at scale.
- Elegant multiprotocol design bridged legacy and IP.
- Optical Networking (DWDM)
- Multiplied backbone capacity by orders of magnitude.
- Without DWDM, MPLS and IP would have hit bandwidth walls.
- BGP (Border Gateway Protocol)
- The “glue of the Internet.”
- Scales routing to a global level; without BGP, TCP/IP alone couldn’t form today’s Internet.
I could probably go on to include things like DHCP, OSPF, EIGRP, etc., etc. The point of this post though is that MPLS is still in almost every backbone—but its dominance is being eroded by SR and SD-WAN. Still, in terms of elegance, influence, and longevity, MPLS earns a strong case as one of the greatest networking technologies ever devised.
Why It Might Not Be one of the Greatest
But calling it the greatest is certainly debatable:
- Complexity – MPLS requires a heavy control plane (LDP, RSVP-TE, MP-BGP, etc.) and deep operator expertise. That complexity has driven some toward simpler IP-only approaches.
- Cost/Lock-in – MPLS was often tied to expensive carrier offerings; enterprises sometimes felt locked in.
- Rise of Alternatives – Segment Routing (SR-MPLS, SRv6), SD-WAN, EVPN, and plain IP with modern hardware are displacing MPLS for new networks. (I can already hear the comments – Segment Routing is still MPLS, and I completely agree).
- SD-WAN has clearly taken some MPLS market share – heck it targeted MPLS from its introduction, and I can already hear some readers jumping out to their chairs chanting MPLS is dead!
- Let’s look at this MPLS vs. SD-WAN a little deeper below
- End-to-End Internet – Unlike TCP/IP, which is universal, MPLS is really a provider technology. End-users rarely touch it directly and most have no idea it is even present.
MPLS vs. SD-WAN
| Feature | MPLS | SD-WAN |
|---|---|---|
| Origins | Late 1990s, carrier-driven | Mid-2010s, enterprise-driven |
| Transport | Private, label-switched paths over carrier backbone | Overlay tunnels (IPsec/GRE) over any IP transport (MPLS, broadband, LTE, 5G) |
| Performance | Deterministic, engineered paths, guaranteed QoS | Best-path selection using real-time metrics (latency, jitter, loss) |
| Cost Model | Premium; tied to service provider contracts | Cost-optimized; uses commodity Internet links alongside MPLS |
| Flexibility | Static once provisioned, slower to adapt | Dynamic, policy-driven, cloud-integrated |
| Security | Implicit trust within provider core | Encrypted tunnels, end-to-end enterprise control |
| Use Case Sweet Spot | Global enterprise WANs requiring strict QoS and SLAs | Hybrid WANs, cloud adoption, branch flexibility, cost reduction |
MPLS deserves recognition as the greatest service provider enhancement ever invented after TCP/IP. It enabled telcos to deliver private, engineered WANs at global scale, something IP alone could not do.
SD-WAN, however, represents the next evolution: moving control from the carrier back to the enterprise, leveraging cheap Internet access while maintaining performance and security through overlays. That said the SD-WANs may be carried over service provider MPLS infrastructure and don’t even know it!!!!
Here we are in 2025 – that’s right, more than 25 years later and MPLS soldiers on carrying the vast majority of the Internet Traffic worldwide. If TCP/IP is the “greatest protocol of all time” because it enabled the global Internet, MPLS might be seen as the greatest carrier-scale enhancement ever invented. It bridged the gap between best-effort IP and the deterministic needs of telcos and enterprises for nearly two decades.
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