// Coherent
DSP Power Budget Coherent 400G Data Center TCO Network Design Optical Networking LPO Energy Efficiency

DSP Power: The Budget Item That Keeps Growing

A 400G coherent port draws 16–20W. At 64 ports per chassis: 1.3kW just for optics. DSP power is a real constraint in dense deployments — and most capacity plans ignore it.

Rene Fichtmueller / 2026-05-08 / ~2 min read min read
Coherent 400G 800G QSFP-DD OSFP OpenZR+ OpenROADM Optical Networking Pluggable Supply Chain

Pluggable Coherent in 2026: What's Shipping, What's Vaporware

800G ZR modules are announced. 1.6T is on the roadmap. Meanwhile, half the 400G ZR+ SKUs take 14 weeks to ship. Here's what's real in pluggable coherent today.

Rene Fichtmueller / 2026-05-07 / ~2 min read min read
400G Coherent ZR ZR+ DWDM Optical Networking WAN Network Design TCO OpenZR+ OpenROADM

400G ZR vs ZR+: You're Asking the Wrong Question

The ZR vs ZR+ debate dominates every WAN discussion. It's the wrong frame. The real question is whether you understand your link budget well enough to buy either.

Rene Fichtmueller / 2026-05-05 / ~2 min read min read