Yes. HT8xx products can work with 4-wire analog phones, but only the TIP and RING pair is actually used for operation. These are the two middle wires of the RJ-11 interface, and they are the only ones connected to the device’s hardware board. This means 4-wire phones function normally, but the ATA only uses the standard 2-wire analog signaling.

Pick up the handset of a phone connected to an FXS port and dial *** to open the IVR. Then dial 02, and the device will announce its current IP address. This applies whether the unit is using DHCP, Static IP, or PPPoE mode.

Yes. All models support T.38 Fax Relay up to 14.4 kbps, and automatically switch to G.711 Pass-Through if needed, ensuring reliable fax transmission.

Dial *** then 7X, where X is the port number.
Example: To call the phone on FXS port 1, dial *** → 71.
This works even without any SIP registration.