Hi folks. I'm wondering if anyone has seen this before.

I have a customer that's using a T1 connected to a Cisco 243x IAD for VoIP phone service. The IAD is handing off several FXS lines to a customer-provided Allworx 10x PBX.

On the PBX the customer is running the built-in IVR. The problem occours when a call comes in and is picked up by the IVR. As expected, while the person is listening to the IVR the port state is "off-hook". However, if the calling party hangs up while the IVR is still playing the port goes "on-hook" for a second, then is pulled "off-hook" again by the PBX. The line stays in an "off-hook" state until the IVR completes then returns to "on-hook". These are loop-start lines off the IAD. I have tried fwd disconnects and supervisory disconnects but they have had no effect. Anyone else have any ideas?

Here's a debug from the IAD:

Code
 Feb 22 14:22:15.242 ET: htsp_timer_stop3 htsp_setup_req
Feb 22 14:22:15.242 ET: htsp_process_event: [2/2, FXSLS_ONHOOK, E_HTSP_SETUP_REQ]fxsls_onhook_setuphtsp_alert
Feb 22 14:22:15.246 ET: [2/2] c2400_set_sig_state: ABCD=0, timestamp=0, sys_time=61198920
Feb 22 14:22:15.246 ET: [2/2] htsp_set_caller_id_tx calling num=npanxx2500 display_info= called num=npanxx0891 
Feb 22 14:22:15.246 ET: [2/2] Caller ID String 80 19 01 08 30 32 32 32 31 34 32 32 02 0A 32 34 38 37 38 34 32 35 30 30 08 01 4F 63 
Feb 22 14:22:15.246 ET: [2/2] htsp_set_caller_id_tx_time Caller ID:FSK_DURING_RING 
Feb 22 14:22:15.246 ET: [2/2] htsp_start_caller_id_tx string length=28 
Feb 22 14:22:15.314 ET: [2/2] do_ring_cadence IDLE->ON (2000)
Feb 22 14:22:17.314 ET: [2/2] do_ring_cadence ON->OFF (4000)
Feb 22 14:22:18.682 ET: [2/2] c2400_report_sig_state: ABCD = 0xC
Feb 22 14:22:18.682 ET: port 2 changed state new state = 12
Feb 22 14:22:18.682 ET: htsp_process_event: [2/2, FXSLS_WAIT_OFFHOOK, E_DSP_SIG_1100]fxsls_waitoff_offhook
Feb 22 14:22:18.682 ET: [2/2] c2400_set_sig_state: ABCD=4, timestamp=0, sys_time=61199264
Feb 22 14:22:18.682 ET: [2/2] c2400_set_sig_state: ABCD=6, timestamp=200, sys_time=61199264
Feb 22 14:22:18.682 ET: [2/2] htsp_stop_caller_id_tx 
Feb 22 14:22:18.682 ET: htsp_timer2 - 500 msec
Feb 22 14:22:18.686 ET: htsp_call_bridged invoked
Feb 22 14:22:18.694 ET: htsp_process_event: [2/2, FXSLS_WAIT_OFFHOOK, E_HTSP_VOICE_CUT_THROUGH]fxsls_waitoff_voice
Feb 22 14:22:19.182 ET: htsp_process_event: [2/2, FXSLS_WAIT_OFFHOOK, E_HTSP_EVENT_TIMER2]fxsls_offhook_dial htsp_dial
Feb 22 14:22:19.182 ET: htsp_process_event: [2/2, FXSLS_CONNECT, E_DSP_DIALING_DONE]
iad#
iad#  ***IVR CONNECTS AND BEGINS TO PLAY***
iad#  ***cALLING PARTY HANGS UP DURING IVR***
iad#
Feb 22 14:22:33.670 ET: htsp_timer_stop3 
Feb 22 14:22:33.670 ET: [2/2] htsp_stop_caller_id_tx 
Feb 22 14:22:33.678 ET: htsp_process_event: [2/2, FXSLS_CONNECT, E_HTSP_RELEASE_REQ]fxsls_connect_disc
Feb 22 14:22:33.678 ET: htsp_timer_stop 
Feb 22 14:22:33.678 ET: [2/2] c2400_set_sig_state: ABCD=12, timestamp=0, sys_time=61200763
Feb 22 14:22:33.678 ET: [2/2] c2400_set_sig_state: ABCD=4, timestamp=750, sys_time=61200763
Feb 22 14:22:33.678 ET: htsp_timer - 950 msec
Feb 22 14:22:34.630 ET: htsp_process_event: [2/2, FXSLS_CPC, E_HTSP_EVENT_TIMER]fxsls_cpc_timer
Feb 22 14:22:34.630 ET: [2/2] c2400_report_sig_state: ABCD = 0xC
Feb 22 14:22:34.630 ET: htsp_timer - 60000 msec
Feb 22 14:22:34.630 ET: htsp_process_event: [2/2, FXSLS_WAIT_ONHOOK, E_DSP_SIG_1100]fxsls_waitonhook_offhook
iad#
iad#  ***(ABOVE) PORT GOES ON-HOOK AND IS IMMIDIATELY TAKEN OFF-HOOK AGAIN***
iad#
iad#
Feb 22 14:23:34.630 ET: htsp_process_event: [2/2, FXSLS_WAIT_ONHOOK, E_HTSP_EVENT_TIMER]fxsls_offhook_wait_timer
Feb 22 14:23:34.630 ET: htsp_timer - 30000 msec
iad#
iad#  ***(BELOW) PORT CLEARS TO ON-HOOK STATE
iad#
iad#
Feb 22 14:24:04.631 ET: htsp_process_event: [2/2, FXSLS_OFFHOOK_ALERT, E_HTSP_EVENT_TIMER]fxsls_alert_timer
Feb 22 14:24:04.631 ET: [2/2] c2400_set_sig_state: ABCD=4, timestamp=0, sys_time=61209858
Feb 22 14:24:06.923 ET: [2/2] c2400_report_sig_state: ABCD = 0x4
Feb 22 14:24:06.923 ET: port 2 changed state new state = 4
Feb 22 14:24:06.923 ET: htsp_process_event: [2/2, FXSLS_PARK, E_DSP_SIG_0100]fxsls_park_onhook
Any ideas would be helpful.

Thanks,

M