I have four routers in a remote location used as an FXO gatway, and its communicating with CM6.1 using MGCP.
Is there a way to check whether the FXO line is connected, and that there is a dial tone available on this port or not?
Correct, there is no way to know without calling. Remember, CO sends dialtone only when phone goes off-hook.
Thanks for the nice rating and good luck.
If you do a 'debug vpm signal' and you see this: htsp_process_event: [2/1, FXOLS_WAIT_DIAL_TONE, E_DSP_SIG_1100]fxols_power_denial_proc
That means there isn't a device giving dial tone normally.
If it's good, you'll see things like CALL_PROC, VOICE_CUTOVER, etc.
Take "debug vpm signal" with "term mon" when making a call, if there is no current loop it will be easy to tell, as it generates an error.
The other obvious test is to call into that line and observe the same debug for incoming ring.