I am using sim808 module to send sms from my device. Everything works fine when I use a local sim card (within the same circle, I'm based out of India).
However the sms are not coming through when using a roaming sim card. The sms show as sent from the sim808 side but never reach the destination.
For example, my sms gateway is based out of New Delhi. When I use a Delhi sim card all is good. However when I use a sim card from bangalore the issue happens.
The sim card is fine as I can send sms through the same sim card using my phone.
Any insight on what could be going on here would be great. Thanks!