As already noted, your main problem is the use of such a long-obsolete device: https://forum.sierrawireless.com/t/beginner-in-the-world-of-gsm-modems-questions-for-open-at/4811/1
As already noted, your main problem is the use of such a long-obsolete device: https://forum.sierrawireless.com/t/beginner-in-the-world-of-gsm-modems-questions-for-open-at/4811/1