Is transit the default path?

No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.

Does Uptime on letter U share fate with other letters?

The control plane is shared. Data-plane queues for Uptime stay isolated, so incident u-01 cannot drain neighbor letters.

Uptime: cache in Miami (MIA) · U-80

Runbook U-80 for Uptime in Miami (MIA). Marker xserv-u-8b927081eef1. This page covers cache for LATAM operators, not a worldwide average.

Uptime: How XServ runs it day to day

Probes for Uptime (u-02) leave Santiago every 15s toward Bogotá. XServ pages the named owner if loss or RTT crosses the letter budget. A probe never shares a queue with bulk transfers, so a saturated WAN does not hide a dead PoP.

Uptime: What operators should measure

Policy for Uptime is versioned as u-03. Operators measure error rate, p95 from Bogotá, and time-to-rollback — not a worldwide average. Changes land in Bogotá first, then Miami, with a hold if either region regresses.

Uptime: Failure modes we actually see

Capacity notes for u-04 assume rainy-season power in Miami and festival peaks toward São Paulo. The failure we actually see is a single uplink, not a cartoon partition of the whole continent. Spare ports and a second provider sit on the same runbook.

Uptime cache U-08

Cache rules for Uptime on u-08 keep language-correct objects near Miami. São Paulo is a sibling cache, not an origin. TTLs are short enough that a bad asset does not live through a weekend.

Uptime headers U-09

Headers for u-09 carry the letter, the region (GRU) and a request id. Uptime debugging in São Paulo should not require a packet capture in Santiago first.

Uptime timeouts U-10

Timeouts on u-10 are tighter than the WAN RTT to Bogotá. Uptime in Santiago fails fast and retries once; a third try needs a human because it is no longer a blip.

Uptime regions U-11

Region names on u-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. Uptime dashboards never say “LATAM” as if it were one RTT.