To configure a PRI gateway, start by connecting the E1/T1 cable from the telecom provider to the PRI port and linking the LAN port to your network. Access the gateway’s web interface using its default IP address and configure the network settings by assigning an appropriate IP address. In the E1/T1 settings, select the correct line type (E1/T1), signaling mode (ISDN PRI), clock source, and framing/coding settings based on your provider’s requirements. Next, set up a SIP trunk by entering the SIP server details, authentication credentials, and port settings. Configure call routing rules to define how calls are processed between the PRI and VoIP systems, ensuring proper inbound and outbound call handling.