Simplified DWDM vs. traditional DWDM: balancing architectures and use cases

Simplified DWDM vs. traditional DWDM at a glance 

Traditional DWDM is typically built around dedicated transport hardware, with optical functions handled by transponders or muxponders and a clearer separation between IP and optical layers. Simplified DWDM, also referred to as IP over DWDM (IPoDWDM), shifts optical interfaces into routers using coherent pluggable optics and open line systems, reducing the need for separate transport layers in some cases. 

Pluggable optics can be used directly in routers or switches where they are sufficient for the service, while transponders or muxponders are used where they add value, such as to improve fiber utilization through breakout or aggregation. Each approach reflects different priorities in network design, from control and capacity optimization to flexibility and operational simplicity.

What separates simplified and traditional DWDM architectures

Traditional DWDM architectures were originally designed for long-distance, high-capacity service provider environments, where maximizing reach, scale, and control at the optical layer is critical. This led to solutions built around dedicated, chassis-based transport systems with vertically integrated functionality, where optical transport is managed as a cohesive system, often within a single-vendor platform. This enables advanced capabilities such as aggregation, wavelength management, and detailed performance control, but also introduces additional hardware, complexity, and operational overhead. 

Simplified DWDM, also referred to as IPoDWDM, takes a different approach by shifting more optical functionality into routers and switches through coherent pluggable optics, combined with open line systems for amplification and transport. Instead of relying on vertically integrated transport platforms, the optical layer can be disaggregated into its core components and applied only where needed, allowing different elements to be combined more flexibly across the network. This reduces the amount of dedicated hardware and aligns more closely with how modern networks are deployed and operated. 

The result is not just a difference in form factor, but in how networks are designed and operated. Traditional DWDM prioritizes control and maximum utilization of optical resources through integrated transport systems, while simplified DWDM prioritizes speed of deployment, operational simplicity, and flexibility through more disaggregated architectures. These architectural differences explain why each approach fits different scenarios across data center interconnect, metro, and regional networks.

Simplified DWDM speeds up deployment for NDIX 

As international ethernet exchange NDIX upgraded its DWDM backbone to 100G with a path to 400G, the focus was on making migration fast and avoiding a larger rebuild. By introducing an open line system that works with existing infrastructure, they simplified their DWDM architecture by replacing part of the existing optical transport layer, allowing links to be brought into service much faster. 

As Thomas van de Lagemaat, Manager NOC & Operations at NDIX, puts it: “In theory, it sounded very simple, almost too good to be true. When we actually tested one of these open line systems, we were blown away that it really was as easy in practice. Jobs that used to take a couple hours at night are now completed in a matter of minutes.” Read the full NDIX case study. 

Hybrid DWDM reduces fiber use and complexity for DE-CIX

At global internet exchange DE-CIX, rapid traffic growth increased both capacity demand and pressure on fiber and cross-connect costs. Instead of scaling link by link, they used compact muxponders to aggregate multiple 100G services into 400G wavelengths. These muxponders are combined with open line systems and pluggable optics to form a hybrid DWDM architecture. This way, simplified and traditional DWDM approaches are combined to increase capacity while reducing fiber usage and complexity. 

Dr. Thomas King, CTO, DE-CIX, describes the outcome this way: “The solution delivers more capacity per wavelength, maximizing what we get out of each fiber. This allows us to significantly cut our cross connect lease expenses and make our commercial offering even more competitive.” Read the full DE-CIX case study. 

Geneseo simplifies architecture for long-term flexibility

As communication service provider Geneseo moved away from complex, bundled designs by separating Layer 1 transport from Layer 3 routing, creating a simpler and more modular architecture. This made it easier to scale and change the network without introducing dependencies between layers, or having to upgrade everything at once from a single vendor – a common limitation in more traditional DWDM architectures. 

Ron Hartman, Central Office Manager, Geneseo Communications, explains it this way: “The separation between Layers 1 and 3 allows me to work on routers seamlessly. I can take a router out of service, make changes, and know it won’t impact anything else on that ring.” Read the full Geneseo case study. 

Combining the best of simplified and traditional DWDM – a hybrid approach

The shift is not about choosing between simplified and traditional DWDM, but about removing the tradeoffs of both by combining their strengths where they add value. Instead of relying on transponder-heavy, tightly coupled systems, or limiting the network to what can be handled directly in an IPoDWDM model, a hybrid approach allows each part of the optical layer to be used where it makes sense.  

This results in a more compact and flexible architecture that introduces transponder functions where they add value.

Explore Smartoptics open optical networking solutions

Smartoptics offers open, compact optical networking solutions that support a hybrid approach, combining pluggable optics with transponders, muxponders, and open line systems without hidden license fees.