Well, im developing SMS Gateway, i was thinking about the featrues i should implement in, so i reviewed some sms gateways like SMSNOW, SMS studio, Ozeki etc
any way i almost finished the sms gateway implementation but i came a cross a feature in almost all sms gateway which is allowing the user to specify TON/NPI for SMSC and ESME
i understand that when the sms gateway is preparing to send the sms using SMPP protocol it would need to parse the sender/reciever number and based on that specify TON/NPI and i understand that its great to allow you to Override the defaults and specify your own TON/NPI
but what i dont understand is why all sms gateways give you option for specify your own TON/NPI for the smsgateway when it act as SMSC (when he is recieving SMS not sending them)
what the sms gateway would do with the specified TON/NPI when it recieve an smpp SMS????