Unstructured Supplementary Service Data

[babbltd-admin]

Unstructured Supplementary Service Data (USSD), sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator's computers. USSD can be used for WAP browsing, prepaid callback service, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network.[1]

[babbltd-admin]

A few things to note about USSD:

USSD is session driven. Every request we send you will contain a sessionId, and this will be maintained until that session is completed
You will need to let the Mobile Service Provider know whether the session is complete or not. If the session is ongoing, please begin your response with CON. If this is the last response for that session, begin your response with END.
If we get a HTTP error response (Code 40X) from your script, or a malformed response (does not begin with CON or END), we will terminate the USSD session gracefully.
Your USSD Menu should not contain special characters as the telcos are unable to render such content, which could lead to disruptions in accessing your USSD services.