Warning message

  • Cisco Support Forums is in Read Only mode while the site is being migrated.
  • Cisco Support Forums is in Read Only mode while the site is being migrated.


Unanswered Question
Jul 28th, 2010
User Badges:

I have a cisco 3845 with VIC2-4FXO and cisco callmanager

I connected this box to PBX

the senario is some one from pbx phone dials 9 and then router will send secondary dialtone after that the user hears cisco dialtone and then  will dial four digit ip phone number and then router will send call to cucm (version 7) and Ip phone will ring ..

the problem is when the user hang up the phone on pbx side, the ip phone will ring and ring and ring!! and fxo port will remain off-hook

my cisco router ios is 12.4 24(T)

I searched many thing . most of configuraitions that i have found were out of date and useless on my IOS version.

any idea please!!!!!


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Steven Holl Wed, 07/28/2010 - 12:47
User Badges:
  • Cisco Employee,

This is a classic FXO disconnect supervision issue.

Signaling a far-end disconnect via FXO happens via:

power denial


call progress tone

From a detection perscpetive, the first two are enabled by default on the router.  The latter is not, and is configured with:

voice-port x/x

supervisory disconnect dualtone mid-call

timeouts call-disconnect 5

timeouts wait-release 5

You should find out how the PBX is signaling disconnect supervision, so that you know what you need to look for.  If it is power denial, find out the power denial duration and tweak the router port according to match.  If it is sending a tone, the above config should fix it, assuming it is sending a valid CP tone accordiong to the CP tone defined.

ehsan.emad.cisco Wed, 07/28/2010 - 23:57
User Badges:

please provide me some debug commands to find out pbx action about disconnect


This Discussion