Call termination disconnect signal

[flumplover]

 I am using a patton 4112 FXO adapter to connect analogue phone line into a 3CX PBX. The adapter answers incoming call by sending to voicemail, once the caller hangs up the landline isn’t released by the adapter. It appears to be a settings issue on the adapter, does anyone know what disconnect signal is sent from the exchange when call is terminated?

[Gondola]

When the caller hangs up then dial tone will be there unless your PBX is holding the line open. So having a timeout on your answering machine is a pragmatic solution.

[flumplover]

If the caller hangs up after leaving a message then the call should be considered has ended, to know exactly what is happening would need to be able to listen in on the line with a linesman’s phone that doesn’t place a loop on the line. 

As an interim I’ll reduce the maximum recording time for a message to be left to reduce how long the line is kept open after caller disconnects

[Gondola]

For customer security Openreach have already set a timeout so that dial tone is resumed on lines where the caller does not disconnect. So if your PBX does not effect a disconnect then having a timeout is appropriate.

[flumplover]

The PBX is set to wait for dialling tone before sending DTMF digits out to make the call.

To make calls external to the PBX I dial 9 followed by the digits.

 
So if I dial 917070, the 9 is the signal to the PBX to seize the talk talk line then wait for dial tone then dial 17070. This works without issue. 

Also, I should add on a incoming call that is picked up by voicemail that if the caller leaves a message and follows the prompt to press #0 to save the message then the call is terminated from the PBX side.

But relying on callers to do that isn’t a good idea, human nature is just to leave message and hang up unfortunately. This has given me a idea though, if limit maximum length of message that can be left this will reduce the time that the line waiting to be released from the PBX end, currently it’s set to 2 minutes.

If can’t get the adapter to recognise that the call has been terminated from the landline side then that’s the only option I can see as viable.

*** For clarification, I am a personal customer, not a business customer ***

[Gondola]

Does your device recognise dial tone.

TalkTalk Support wonder if you're a business customer?

[flumplover]

Contacting the manufacturer won’t be helpful here. I know how to change settings regarding the landline configuration on the adapter. 

The manufacturer won’t know what disconnect signal is sent by TalkTalk.

is there anybody technical from TalkTalk who can supply this information?

[Gondola]

If you seriously want to know about the device settings and how it is supposed to work then ask the manufacturer.

In answer to the question. Dial tone.

[flumplover]

Yes I am totally serious, it’s a solution that works for me. It does the job, just because it’s end of life doesn’t mean it’s not fit for purpose. Granted once the POTS telephone line get switched off it will be unneeded but that’s 2025 at the latest so for now it’s still going to be needed. If wasn’t serious I wouldn’t be asking 

[Gondola]

Are you serious? A business grade VOIP device that the manufacturer has declared end of life on. And you post on a home phone forum.