Notify subscribers of missed calls
USSD Collect Call is used to request B to pay for the call from A. A issues a USSD request to instruct party B, who will then be asked if he accepts or declines to charge for the call. If B accepts the service, then the A and B parties are connected.
1. Blacklist
2. Whitelist
3. Call Limit
4. Answer call by Prefix
5. Auto Subscribe
6. Roaming Restrictions
7. Report