// PAM4
400G PAM4 FEC Forward Error Correction KP4 Pre-FEC BER Network Monitoring Signal Integrity Lane Diagnostics Data Center Networking NRZ Optical Networking oFEC RS544 MPO Connector Chromatic Dispersion OSNR

400G Does Not Fail — It Degrades

An interface can be up while the link is already operating outside a stable margin. At 400G, a link being 'up' is not a useful indicator of health.

Rene Fichtmueller / 2026-04-15 / ~3 min read min read
Optical Networking 800G 400G Deployment Data Center Optical Transceiver OSFP QSFP-DD PAM4 Network Design TCO Fiber Infrastructure

800G: The Upgrade That Exposes Everything

A $350 optic turned into an $18,000 problem. Not because the optic failed — because nobody cleaned the connector.

Rene Fichtmueller / 2026-04-05 / ~1 min read min read