Hello,
I have previous experience working with SMS gateways having been in the telecommunications industry for some 24 years.
My past work included designing and integrating with SMS gateways using SMPP, HTTP, REST, SS7 and SIGTRAN protocols.
I am familiar with both Kannel and Jasmin having designed API's for these for purposes such as integrating with CRM systems, SMS blasters (bulk notifications) and SMS to email and email to SMS services.
Please feel free to contact me to discuss your requirements.
Sincerely,
Stephen Lombard
Your API Expert