The VoIP GSM Gateway is the next big thing in corporate IP telephony. It is intended for businesses that require additional lines of mobile communication. It includes four slots for mobile SIM cards (4,8,16, and 32 ports are also available) and so offers four simultaneous connection channels. It is used in conjunction with an IP PBX system. Users should also use the VoIP soft switch to log in. Each of the four channels can be individually programmed, and communication is handled by an IP-PBX.