Is transit the default path?

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

Does TLS on letter T share fate with other letters?

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

TLS: cache in Miami (MIA) · T-68

Runbook T-68 for TLS in Miami (MIA). Marker xserv-t-738239394ce1. This page covers cache for LATAM operators, not a worldwide average.

TLS: How XServ runs it day to day

Probes for TLS (t-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.

TLS: What operators should measure

Policy for TLS is versioned as t-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.

TLS: Failure modes we actually see

Capacity notes for t-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.

TLS peering T-07

Peering for TLS (t-07) prefers the IX fabric that already carries last-mile ISPs in Bogotá. Session counts and prefix limits are on the same page as the Miami backup path.

TLS cache T-08

Cache rules for TLS on t-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.

TLS headers T-09

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

TLS timeouts T-10

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