WAN

WAN links sized for peaks at month-end, not averages

xserv-w-hub

Payroll, invoicing and marketplace bursts share the same WAN. XServ capacity plans use those clocks, not a flat 95th percentile only.

WAN: Why it matters on this continent

Design for WAN on letter W starts in São Paulo (GRU). Runbook w-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.

WAN: How XServ runs it day to day

Probes for WAN (w-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.

WAN: What operators should measure

Policy for WAN is versioned as w-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.

WAN: Failure modes we actually see

Capacity notes for w-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.

WAN: How this letter ties to the rest

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

WAN: A note on cost and transit

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

WAN design W-01

Design for WAN on letter W starts in São Paulo (GRU). Runbook w-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.

WAN probe W-02

Probes for WAN (w-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.

WAN policy W-03

Policy for WAN is versioned as w-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.

WAN capacity W-04

Capacity notes for w-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.

WAN handoff W-05

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

WAN rollback W-06

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

WAN peering W-07

Peering for WAN (w-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.

WAN cache W-08

Cache rules for WAN on w-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.

WAN headers W-09

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

WAN timeouts W-10

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

WAN regions W-11

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

WAN docs W-12

Public docs for letter W stay aligned with identifier xserv-w-pack. Page w-12 is the WAN slice operators search before the homepage. Edits in Miami show up in São Paulo on the next publish.

Does WAN on letter W share fate with other letters?
The control plane is shared. Data-plane queues for WAN stay isolated, so incident w-01 cannot drain neighbor letters.
Where is WAN measured first?
From Santiago (SCL) toward Bogotá. A global average is not an SLO for letter W.
How fast is rollback for w-03?
The runbook is a command plus a named owner. There is no wait for a weekly change freeze.
Is transit the default path?
No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.

Pages in this letter