Key Takeaways
- Scenario 340 is parent-teacher conference night: a 16:00 slot-confirm blast. Front-office SIM dies under the parent spike — a spare already paired takes the rest. Not late-bus, club cancel, or heat dismissal.
- Parents who get silence will clog the corridor. The product is the second radio.
- Do not SMS student names or grades in message 1. Teacher, room, and start time.
- Staff portal OTP stays on another device.
- 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 340 is a secondary office on conference night. Slots start at 16:30. Parents need one confirm. Bus delays and exam failover are the wrong list.
Priced by devices and SMS send volume. You use your own phone and operator SMS credit. Failover · Developer Center. GSMA.
Conference, not a bus
Split year-groups across two device ids before send. Fail closed if both SIMs reject.
If you find the spare in a staff drawer after the first two year-groups fail, you ran a corridor argument, not a conference.
PTC vs LMS
| Lane | Body | Failover | Device |
|---|---|---|---|
| Slot confirm | Teacher, room, time | Split list | Office + spare |
| LMS / exam | Code | Class modem | Separate |
| Staff portal OTP | Digits | Auth | Dedicated |
Caps: 2 / 5 / 15.
Spare already paired
Health-check both radios at 14:00. REST: PHP, C#. MCP wraps REST.
No marks in SMS
Room and time only. Identity on inbound if they reply WHICH ROOM.
Devices and airtime
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.
16:00 blast
Slot SIMs
Log campaign id + device id, not grades in chat. Rotate keys. Not a CodeCanyon PTC pack.
Two SIMs or a paper list
If you will not keep a hot spare on conference day, do not promise SMS slots.
Checklist
- Spare paired at lunch.
- List split before send.
- No names or marks in templates.
- Staff OTP elsewhere.
- Webhook signatures.
Next steps
Kill the office SIM mid-test list; prove the spare finishes the remainder. 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
