Gateway System

Gateways connect legacy phone equipment (PBXs, ACDs, voicemail systems, etc.) to modern VoIP systems and services. Asterisk supports many different communications protocols from both the modern world of VoIP and from the legacy PSTN. This makes it a powerful tool for building gateways and protocol converters.

A VoIP Gateway allows you to convert between a legacy telephony connection, such as E1/T1/PRI and a modern VoIP connection using SIP. This is known as "digital gateway" because the voice media is converted between a digital TDM connection and a VoIP connection. The conversion can go from SIP to TDM, TDM to SIP or even SIP to SIP for the purposes of failover or transcoding. In a TDM-to-SIP deployment, the gateway significantly reduces operating costs by connecting a legacy business phone system with dynamic SIP trunking services. SIP-to-TDM deployments use the VoIP gateway to connect a modern SIP communications system with T1/E1/PRI service from legacy carriers.