CID

The FXO voice subscriber line receives the calling identity information from the PBX. The FXO interface receives the modulation information of the calling identity information from the PBX between the first and second rings. (This is the default situation. Use the cid ring command to configure the time for CID check.) Then, the calling identity information undergoes FSK demodulation and parity check. The function of sending calling identity information is checked after the parity check succeeds. If the function is enabled, the calling identity information is sent to the IP network. If the function is disabled, the identity information is empty.