Supervisory Disconnect Signaling methods question

Unanswered Question


So we were running into an issue with our UC520 where calls would not hang-up properly (green light on the UC would stay on even if we physically disconnected the cable, on a PSTN line).

After talking to a guy at Cisco, he told me to check with our phone provider which type of disconnect signaling they were using.

Our provider uses Loop Start by default, but they can change to Ground Start if requested.

I've found some documentation on Cisco about Ground Start, but don't know which one is "better" (if even it botters to have a "better" disconnecting method ?).


Should I use Loop start, or ask them to switch to Ground Start.

In either case, can someone point me to some kind of documentation on how to configure them properly.



I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)

Thanks for the reply Glenn,

I've read the second link which was helpful to clarify the difference between those two methods.

But the first link is the exact one I've first posted

And in this document, I can't find how to configure either Loop Start or Ground Start methods. I do see the commands for battery reversal and tone based methods, but nothing on Loop or Ground start... or am I not fully understanding this part :

Configure the FXO Port to Support Power Denial in Cisco IOS Software Release 11.3MA and Later

The supervisory disconnect signal command turns on support for power denial recognition. This is the default configuration. Configuring the no supervisory disconnect signal command turns off support for power denial in this release, and also enables support for basic supervisory tone disconnection. Refer to Configure the FXO Port to Support Supervisory Tone Disconnection.

FXO_Paper(config)#voice-port 2/1/1 FXO_Paper(config-voice)#supervisory disconnect signal FXO_Paper(config-voice)#end FXO_Paper#

Do I have to understand that by simply enabling supervisory disconnect signal, my UC will support Loop Start and Ground Start...?

Glenn Quesenberry Fri, 11/06/2009 - 12:28

You can also reference the "Configuring FXO & FXS Ports" section of this document. This will require CLI configuration.  If you continue to have issues after using this document, I would recommend opening a TAC case for TAC to assist you with the configuration.




This Discussion

Related Content