Does Backbone on letter B share fate with other letters?

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

Where is Backbone measured first?

From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter B.

Backbone: handoff in São Paulo (GRU) · B-53

Runbook B-53 for Backbone in São Paulo (GRU). Marker xserv-b-c9c8d0a963b6. This page covers handoff for LATAM operators, not a worldwide average.

Backbone: How this letter ties to the rest

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

Backbone: A note on cost and transit

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

Backbone: Why it matters on this continent

Design for Backbone on letter B starts in São Paulo (GRU). Runbook b-01 keeps a single owner, a written rollback, and a traffic split that can be reversed without a global freeze. Neighbors in Santiago only take overflow after the local pool fails a health window.

Backbone rollback B-06

Backbone peering B-07

Peering for Backbone (b-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.

Backbone cache B-08

Cache rules for Backbone on b-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.

Backbone headers B-09

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