OpenVox DGW-L1 T1/E1 Gateway is an open-source Asterisk-based VoIP Gateway solution for operators andcall centers. It is a converged media gateway product. With a friendly GUI, users may easily set up their customized. Also, secondary development can be through AMI (Asterisk Management Interface). The DGW-L1 T1/E1 Gateway helps one software- selectable T1/E1/PRI interface with supports up to 30 concurrent calls.