GSM Terminal
A GSM Terminal is a type of modem that uses a SIM card like a mobile GSM phone. The GSM Terminal can process a SMS every 5 seconds. You can connect multiple GSM Terminals.

1) Via the V.24 line (2-way SMS)
2) Via a 'Small Device Server' (2-way SMS)

Dial up via modem
The Dial up service is offered in these countries. A SMS can be sent every 12 seconds.

3) Via the V.24 line and asynchronus modem (1-way SMS)
4) Via Internal IBM i™ modem (1-way SMS)

Gateway
Gateways can handle as much as 40 SMS per second. Other SMS Gateways using HTTP interface or the UCP protocol can be implented on request. It applies for both the 'Dial up Service' and SMS Gateways that these services can be accessed without special hardware.

5) Via a Gateway on the Internet (1-way SMS)

Available Gateways
Gateway www.clickatell.com (1-way SMS) http://www.clickatell.com/developers/api_http.php (Worldwide)
Gateway www.cpsms.dk (1-way SMS. Worldwide)
Gateway www.imez.se (1-way SMS. Sweden only)
Gateway SMSPRO Telenor (2-way SMS. Sweden only)
Gateway www.labyrintti.com (1-way SMS. Finland only)
Gateway SMS1919 www.compaya.dk/produkter.html (1-way SMS. 2-way SMS in Denmark only)