IP GSM Gateway / SIP to GSM Gateway
A Voice Over IP GSM gateway will connect to a Voice Over IP Telephone system / IP PBX that allows the use of IP trunks. IP trunks are an alternative to traditional analogue or ISDN telephone lines and allow telephone calls to be made via the internet to an IP service provider who can break out the calls to the traditional telephone network. A phone system with IP trunk capability can utilise the IP GSM Gateway as an alternative to making calls via the internet. The IP GSM Gateway will sit on the network and calls from extensions to mobile phones will be routed via IP to the IP GSM Gateway and delivered directly to the mobile phone GSM network. The most common type of IP GSM gateway uses SIP protocol to GSM.