Hello, everyone!
You can run the display pstn state command to query the physical-layer running status, physical-layer management status, service running status, service management status, and subscriber line status of one or more PSTN ports.
To query the information in ESL user mode, run the config command to enter global configuration mode, and run the esl user command to enter ESL user mode.
To query the information in pstnport mode, run the config command to enter global configuration mode, and run the pstnport command to enter pstnport mode.
Thanks.