Understanding and optimising transceiver efficiency using internal metrics for improved power savings#

Gerhard Stein (Flexoptix GmbH)

• Why: Transceiver power draw is a growing slice of DC and WAN opex, and this is one of the few talks showing how to extract savings from data the optics already expose — no hardware swap required. Squarely in the PM's physical-optics territory.
• What: An analysis of Versatile Diagnostics Monitoring (VDM) metrics in modern (>100G) optical transceivers, focused on Thermoelectric Cooler (TEC) current, correlated with temperature and cable length, to find operating conditions that minimize power while holding performance. Software prototypes were built to evaluate and visualize transceiver efficiency in Watts using real-world VDM data. (from abstract only)
• How: TEC current acts as a proxy for how hard the module is working to hold its temperature setpoint; correlating it with temperature and cable length across real deployment data reveals which optics and link types operate inefficiently and quantifies the per-link watts.
• Where applicable: Any fleet of >100G pluggables that expose VDM — the metrics come from the transceiver, not a specific switch, so the technique is broadly transferable to DC, metro, and WAN optics. Caveat: the speaker is from a transceiver vendor, so expect some product framing around a genuinely vendor-neutral technique.