FXS port problem

[alessandro.dona]

Hi,

i have a GSM adapter plugged into a fxs port.

If i place a call from a IP phone everything works fine. If i put on hook the ip phone and try to place another call i get a busy tone and the only way is to unplugs and plugs again the cable that connect the fxs port with the gsm adapter.

I suppose it's a signaling problem

here is the voice port config

voice-port 2/1/0

no vad

compand-type a-law

no comfort-noise

cptone IT

timeouts call-disconnect 3

timeouts wait-release 3

bearer-cap Speech

any idea?

thx

[bgibson]

Have you tried both loop and ground start?

[alessandro.dona]

Yes I have!

[guilhem.perez]

Hi,

I meet the same issue. Do you solve this issue?

Thanks

[paolo bevilacqua]

Hi, the problem is due to the gsm adapter. If it doesn't go on-hook for any reason, it's normal that you call and find it busy.

For this reason it is recommended to use GSM adapter with either BRI or IP/SIP interface.

[guilhem.perez]

Hi

thanks answering so quickly.

So I can't use a GSM adapter with FXS

[paolo bevilacqua]

Is not that you can't, but you must make sure that it goes on-hook and doesn't keep the line busy.

Perhaps it expects power denial from the router, or a disconnect tone, all thing the router can do, but you must check what your gsm adapter wants.

With ISDN BRI, there is no problem like that so it's much easier.