The DGW100 digital VoIP gateway (DGW100) provides signaling and media conversion between VoIP and ISDN networks. A typical application is to support enterprise PBX upgrades to IP when the WAN access is ISDN. The DGW100 supports 1/2/4 T1/E1 ports and up to 512 SIP trunks, to meet the requirement of large and medium-sized enterprises for VoIP services.