CHOOSING YOUR GSM GATEWAY
Once a GSM Gateway has had the relevant SIM cards inserted, the antenna connected and it is powered up, you can simply treat it like an extra telephone line and as such connect it to your telephone system in the same way that you would connect a new telephone line. This means that choosing a GSM Gateway is as easy as deciding what type of telephone lines are available for your phone system, and what spare line capacity you have or require to enable the connection of new telephone lines / GSM Gateway.
For Analogue Fixed Cellular Terminals (Cellroute GPRS) you would connect these to a spare Analogue trunk port of your phone system.
For ISDN2e GSM Gateways (GSM Route BRI) you would connect this to a spare ISDN2e trunk of you phone system.
For VoIP GSM Gateways (Onestream G) you would register this as a SIP trunk on your VoIP phone system.
For the above expamples the phone system would need to be configured to route calls via the specific trunk port that the GSM gateway is connected to. If additional calls are required, then just like a telephone line, your purchase additional units and connect them to additional spare trunk ports on the PBX.
The exceptions to the above are ISDN30e GSM Gateways and In-Line multipurpose Gateways such as the Onestream GFX and GBRI which are designed to connect between the telephone system and telephone lines, filtering off calls as required. These types of units contain multiple line connectivity, with a smaller ratio of GSM channels and examine calls leaving the phone system and use the built in least cost routing to either make the call via GSM or pass the call through to the fixed line telephone network (PSTN/ISDN).
The expample below shows the Onestream GFX connected between the analogue line ports of a telephone system and the Analogue (PSTN) telephone lines. The Onestream GSM Gateway can then route calls via the built in GSM channels, or can pass calls through to the PSTN telephone lines. The Onestream also has built in Voice Over IP capability so can also provide additional routing to a SIP trunk provider or to a branch office using IP.
