OpenVox DGW-L1 T1/E1 Gateway is an open source asterisk-based VoIP Gateway solution for operators and call centers. It is a converged media gateway product. This kind of gateway connects traditional telephone system to IP networks and integrates VoIP PBX with the ISDN seamlessly. With friendly GUI, users may easily setup their customized Gateway. Also secondary development can be completed through AMI (Asterisk Management Interface).
The DGW-L1 T1/E1 Gateway supports 1 software-selectable T1/E1/PRI interface and supports up to 30 concurrent calls.