Related to Network-initiated USSD/PUSH or USSD/A2P :
- to start NI request, use oper=ussr
- to continue dialog in that NI, use oper=ussr
- to end dialog, use oper=ussn
Related to text pushed to the phone/device:
- use: %0A as enter
- use: %20 as space
Basically, RFC3986 explains ¹ percent-encoding mechanism, ² query component and ³ path componentTest NI USSD from Linux console
Example: curl “http://127.0.0.1/usgw/ussd.php?id=ni/ussd2&msisdn=88210071&operation=ussr&text=YateBTS%0AEnter%20PIN%20to%20approve%20payment%20of%20Amount%201%20USD%20at%20merchant%SS7Ware.%0AFees:%10.00%20USD.&code=199©params=code,text,id“
USSD NI (Network Initiated)

USSD UI (User Initiated)
