The Hypermedia HG212 Dual SIM GSM Gateway is a simple to install GSM gateway that connects to the ISDN2e Trunk port of a telephone system to enable extension users to make calls to mobile phones using standard GSM mobile phone SIM cards. The reason for using a GSM gateway is to provide low cost calls to mobiles using standard mobile phone tariffs, usually the bundled minute tariffs which enable calls to all networks for a fixed monthly rental. Many companies also use GSM gateways to enable free calls to and from their mobile workforce by taking advantage of the free calls between mobiles on the same company plan that many mobile phone operators provide.

Hypermedia HG-212 Datasheet

Hypermedia HG-212 Manual