Key Takeaways
- A locker PIN is authentication. A “new locker on your street” text is promo. They never share a slot.
- Slot A: pickup codes and expiry. Slot B: overflow / locker-full to the van fleet — not to every subscriber.
- Free is 1 device, 300 SMS lifetime, and 300 contacts. Platform price is devices plus send volume; each SIM spends its own airtime.
- After reboot, canary that codes still leave slot A.
- Idempotency is parcel-id plus locker event, not the consignee phone.
Summary
Scenario 231 is dual-SIM routing for PUDO locker networks — not city van ETAs, not line-haul, not cold-chain probes. Lockers mint codes, expire them, and overflow to vans. Those are three jobs and at most two slots on one chassis plus a spare phone. Service pricing is devices plus SMS send volume. You bring the handsets and operator credit. Free is 1 device, 300 SMS lifetime, and 300 contacts.
Starter allows 2 devices: code radio plus spare. That is not unlimited carrier SMS. Confirm routing in Developer Center.
slot A PIN · slot B overflow · promo never
locker-full pages vans, not the whole list
PUDO lockers are not van ETAs
Consignee: “parcel in locker 14, code, expiry.” Van fleet: “site 14 full, take overflow.” Do not send the PIN to the overflow group. Do not send locker-full slang to the consignee.
If the locker controller retries “door closed” and your worker mints a second PIN, the first code still works on the hardware. Persist parcel-id plus event. One door cycle, one code SMS unless the first POST never accepted.
Locker dual-SIM matrix
| Event | Slot | Failure |
|---|---|---|
| Parcel stowed | A — hashed/short TTL code | Promo footer on the PIN |
| Locker full | B — van roster only | All pickup subscribers paged |
| Code expired | A — one regenerate after human or app | Automatic new PIN loop |
| New locker nearby | Not this chassis | Marketing on the PIN SIM |
Pickup codes vs marketing SIMs
Hash or short TTL. Quiet hours do not apply to “your code expires in 2 hours” if they opted into locker SMS. Promo always honors STOP. Webhooks, DLR.
Locker-full and overflow vans
Slot B is a small roster. After OEM reboot, canary A still owns codes. GSMA SIM.
Devices, volume, and airtime
Peak evenings mint many codes. We meter devices and platform sends. Each operator meters its SIM. Free (1/300/300) is one site proof.
Network-ops operations
Charge, pairing, both balances, slot canary. Setup, Downloads, pricing.
Decision guide
Ship when PINs cannot ride the overflow or promo slot. Delay if one SIM does everything. No-phone-ops: aggregator.
PUDO checklist
- Slot A = codes only.
- Slot B = van overflow only.
- Parcel-id + event idempotency.
- Reboot canary.
- Promo off this chassis.
- Developer Center fields confirmed.
Next steps
Scenario 51 city, scenario 111 line-haul, scenario 171 cold chain.
Related product pages
Jump to the live product docs for this topic—not another long-form article.
- multi-device and dual SIM routingCapacity and failover
- transactional SMS for orders and alertsEvent-driven messages
- SMS delivery reports (DLR)Delivery status tracking
- SMS API documentationLive endpoint reference
