User Manual

Note: Some ITSP only let the FXO for termination function, they do not user use the FXO port for

origination

SIP Call Connecting Answer Mode

Scenario B description:

Hot Line Number” was assigned and the hot line number belongs to SIP device.

a) When the call com from PSTN to FXO, FXO start the Hot line dialing to remote SIP gateway

b) The phone of remote SIP gateway start ring.

c) When the phone was picked up, the remote SIP Gateway sends “SIP 200 OK” signal to FXO port.

d) Once FXO port receives the “SIP 200 OK” signal, FXO port would off-hook to answer the PSTN call.

Scenario C description:

“Hot Line Number” was setting and the hot line number was assigned to another FXS port in same

gateway.

a) When the call com from PSTN to FXO, FXO start the Hot

line dialing to FXS port.

b) The phone start ring.

c) Once the phone was picked up, FXO port would off-hook

to answer the PSTN call.