Is transit the default path?

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

Does Zones on letter Z share fate with other letters?

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

Zones: capacity in Miami (MIA) · Z-16

Runbook Z-16 for Zones in Miami (MIA). Marker xserv-z-879edbfdb41e. This page covers capacity for LATAM operators, not a worldwide average.

Zones: Failure modes we actually see

Capacity notes for z-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.

Zones: How this letter ties to the rest

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

Zones: A note on cost and transit

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

Zones cache Z-08

Cache rules for Zones on z-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.

Zones headers Z-09

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

Zones timeouts Z-10

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

Zones regions Z-11

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