Key Takeaways
- Scenario 640 is live-proctor identity OTP: a second factor before the camera session starts — not exam-week LMS, homework, bells, fees, or admissions.
- A drawer spare misses lock-in. The pair is already taking overflow.
- Parent alerts and homework reminders stay off the ID radio.
- Device caps (2 / 5 / 15) decide whether two rooms can lock in at once.
- Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Free: 1 device / 300 SMS lifetime / 300 contacts. Developer: 25,000 SMS per year.
Android SMS gateway scenario 640 is a remote-proctoring desk. The student must confirm a short OTP so the proctor can lock the room. Period-bell join codes and Sunday homework are the wrong clock: here a late code voids a paid sitting.
Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Multi-device · Developer Center. GSMA.
Proctor ID in the first minute
Idempotency: sitting id + gen. Do not mint a second code because DLR is slow — proctors will see two rooms. Cut overflow by device id on heartbeat.
If IT pages “grab the spare” after lock-in started, the sitting already failed.
ID OTP vs LMS vs parents
| Lane | Clock | Pool | Failover |
|---|---|---|---|
| Proctor ID OTP | Lock-in | Hot pair | Already in pool |
| LMS homework OTP | Evening | Other pool | Must not steal ID SIMs |
| Parent digest | Anytime | Ops MSISDN | May delay |
Caps: 2 / 5 / 15.
Live room cannot wait
Raise OEM ceilings carefully; carrier fair-use still applies. OEM.
Hot spare before lock-in
REST: PHP, C#. MCP wraps REST.
Devices vs voided sittings
Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Free: 300 lifetime. Developer: 25,000 SMS per year. Pricing.
Proctor shift
Canary T-20m. Doze exempt. Setup · Doze.
ID photos stay off SMS
Digits only. Do not log full codes. Rotate keys.
In-room only
If you refuse device ops at lock-in, verify ID in the proctor UI only. CPaaS if you refuse phones.
Checklist
- Two live radios before first sitting.
- Parent SMS off this pool.
- Idempotent sitting + gen.
- T-20m canary.
- Airtime on both SIMs.
Next steps
Kill primary at T-10m in staging; prove lock-in OTP uses spare. Downloads · Docs.
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
- OTP and 2FA SMS on AndroidAuthentication flows
- SMS delivery reports (DLR)Delivery status tracking
- SMS API documentationLive endpoint reference
