The VX 820 Duet supports two types of communication, dial and IP, and has a separate port on the Duet base for each type of communications cable.
The Dial Communications Cable
1. Plug one end of the dial communications cable into the dial port () on the base.
2. Plug the other end of the dial communications cable into an analog telephone wall jack.
The Ethernet Communications Cable
1. Plug one end of the Ethernet communications cable into the ETH port on the base.
2. Plug the other end of the Ethernet communications cable into an Ethernet wall jack or a router.