The Definitive Guide toAI Data Centers
Ask the GuideAboutAccount
Guide › Numbers register › Claim

round-trip propagation floor added by 1,000 km of fiber, before any switching or queuing

~10 msderived

Value kindderived — Derived values are guide calculations; their result is only as fixed as the stated inputs, scope, and method.
As of2026-10-12
SourceGuide derivation from c and n≈1.47; M2 Optics (2012-01-09) · 2 × 1,000 km × 4.9034 µs/km = 9.8068 ms, rounded to ~10 ms; equal-length forward and return routes, propagation only
Reviewchecking…review by 2027-10-12 · slow cadence
Recorded changeslast 2026-10-12 · 2 revisions tracked
Claim idround-trip-propagation-floor-added-by-1-000-km

Where the guide uses it

← Full numbers register — every date-stamped figure in the guide, with revision history.