Is transit the default path?

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

Does High availability on letter H share fate with other letters?

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

High availability: capacity in Miami (MIA) · H-40

Runbook H-40 for High availability in Miami (MIA). Marker xserv-h-b2fe97985355. This page covers capacity for LATAM operators, not a worldwide average.

High availability: Failure modes we actually see

Capacity notes for h-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.

High availability: How this letter ties to the rest

Handoff from letter H High availability into the rest of the platform uses the same request IDs as the gateway. Runbook h-05 names who accepts the ticket after São Paulo pages out. Santiago does not silently inherit the incident.

High availability: A note on cost and transit

Rollback for h-06 is a documented command, not a hope. Transit is billed as backup while High availability prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.

High availability probe H-02

Probes for High availability (h-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.

High availability policy H-03

Policy for High availability is versioned as h-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.