Arista posted its first-ever $3B quarter and raised full-year guidance for the third time this year to $12.6B. The real signal isn't AI: it's the return of a core business once criticized as "too flat," and a supply chain that went from complaining to delivering. The battleground is shifting from scale-out to scale-across.

Broadcom's "Open Ethernet" keynote talked standards on the surface, but really declared that Ethernet will take over in-rack scale-up, NVLink's deepest moat. Open specs grow the ecosystem while in-house silicon collects rent, and behind this two-layer play sits a whole new layer of demand for Taiwan's optical interconnect and CPO supply chain.

400G optical transceivers come in many variants. This guide walks through the common specs — SR8, DR4, FR8/LR8 and FR4/LR4 — covering reach, fiber type, wavelength, lasers, connectors and PAM4 lane rates.