I have written 2 test tools based on OpenSMPP. One allows entry of PDU data in a GUI for ad hoc testing, the other allows a batch of PDUs to be defined in an XML file and sent automatically. I have informal approval from my management to open source them. If they could be included in OpenSMPP that would be great, but I see no sign if activity on OpenSMPP at the moment. If the OpenSMPP team is still active and interested, please contact me and I will get formal approval for their release as part of OpenSMPP. If not, I will create a separate project for them.
This code is now available under the GPL at https://github.com/smpptest/SMPP-Test