I've been purchasing large volumes of sms messages from third party suppliers for a while. These suppliers are not actual telcos but resellers. I can't buy directly from the telcos as I don't have the volume.
I'm having trouble with one. They are supposed to provide messages sent through a specific large local telco but I suspect they're using a cheaper overseas alternative. The only real evidence I have of this is the "message centre" in messages received by my handset is an overseas msisdn.
They are claiming that while they use an SMSC from another country the traffic does not originate from overseas. I smell a big rat here.
Am I interpreting the "mesage centre" correctly. Can it be used to specifically and unambiguously identify a sending telco?
Thanks in advance, any input would be greatly appreciated.