Look onto Kannel: http://www.kannel.org/
We have used it several years ago without any problems on very low hardware.
But we have very low traffic, about 1M messages/day.
We are using a Windows Software called Message Master for SMS MT/MO with multiple carriers around the world. The Software an handle all major SMSC protocols like CIMD2/SMPP/... and also standard modems. As hardware we are using modems from wavecom for various SIM cards and carriers around the globe.
In addition we are diving deeper and deeper into the above mentioned kannel and it looks like it's able to solve our demand for a fraction of the cost.
Look onto Kannel: http://www.kannel.org/ We have used it several years ago without any problems on very low hardware. But we have very low traffic, about 1M messages/day.
We are using a Windows Software called Message Master for SMS MT/MO with multiple carriers around the world. The Software an handle all major SMSC protocols like CIMD2/SMPP/... and also standard modems. As hardware we are using modems from wavecom for various SIM cards and carriers around the globe.
In addition we are diving deeper and deeper into the above mentioned kannel and it looks like it's able to solve our demand for a fraction of the cost.