Call Not hang up after call end


Hi Larry, doesnt the NEC provides busy tone for ending of the call on the SLT as a signal to the user to hangup, as far as I remember before it does … it is short but the FXO just needs 1 to 2 seconds or so to register the hang up before the NEC provides lockout and no tone.

Its been that long since I have needed to work on the NEC Digital systems that I can’t truly remember for SLT services.




I think i need to get my glasses :slight_smile:

But still slt is slt in digital and should provide a hang up tone irrespective of the manufacturer…


Why would you expect an analog (not digital) extension card to provide CPC? An analog phone is not going to provide it to the card to signal a disconnect and the card, should it send CPC to an analog phone is simply going to allow you the luxury of hearing the congestion tone or other, but it too will not hang up.

I can see it of there was a call thru a trunk and the far end disconnected and sent CPC to cause the PBX to disconnect the trunk.


If you ever have an analogue handset left off the hook an audio to let them know to hang up the phone has been embedded in all digital systems for over 20 years… it is what a hotel typically would have as a means of telling the user to hang up the phone by drawing attention to the fact that the handset has not been replaced on the hook…

Ever since PABX’s of old 80s this has been the status quo Panasonic might be different these days, your the expert here.


So the system set up as far as i can understand from the information provided is::

Isabel Asterisk pbx (elastix fork) Voip/SIP to the GS GXW4108 (fxo gateway) to the analogue SLT ports of the Panasonic so that calls from the Panasoinc trunks through the system to the analogue of the Panasonic connected to the FXO gateway to Isabel to some other remote service as far as I am understanding or is it different to that?



So to add to what I have written, it looks like to me the fixed resource his Panasonic is at the office premises so he has used the analogue extensions to connect to an fxo that then connects to an external more flexible system that the panasonic to be able to provide the trunks to the external system being issabel ippbx with SIP phones off the issabel ???

Maybe the person that started this thread should clear this up…


Yes, that is an off-hook tone, not a disconnect tone and is dependent on which device or provider has detected the condition, usually by detecting the circuit is still off-hook. It is a function that follows the disconnect. It is not the extension card that provides that in a PBX, but the sensing of the condition when one end has ended and the other side is still on and the processor of the system generates the tone and sends to the afflicted extension via the card.

In this case, it is a GXW connected to an IP-PBX. It seems clear that when a call is terminated by the IP system, it sends a BYE to the GXW. The GXW in turn, must send something to the SLC16. This part appears to work, given the statement of -
“when analog (TDE 200 Panasonic phones which connected to gateway) hang up the phone , IP phones not hangup and still ringing .it appear when a analog phone try to connect to IP phone”.

So, my thought is that given it is an extension card that expects to have an analog phone that will not react to CPC, off-hook or other tones - other than to let you listen to them it does not send a standard CPC type of tone disconnect.

However, you have hit upon the idea that if one knows what that off-hook tone generation is, then perhaps it could be set in the GXW. The only issue is the amount of time needed for the off-hook tone to come about. But as I suspect that this is generated by the PBX and may not represent a standard for a given country, it may be problematic to find. The off-hook tone by a provider in the UK is different than that in the US and so I suppose also true for the PBX makes. I can find no reference to an off-hook tone in the TDE200 manual or in the 2 versions of the SLC16. I can find others, but nothing of interest.

Thoughts? Go SIP?


Replace the Panasonic would be the best way and use the FXO gateway if he has PSTN and a UCM 6202 unless he needs more SLT then he can add a HT81x.

All handsets could be purchased as an ad hoc if money was real tight… and use GSWave or equivalent for the extensions… if it is a remote side of thing then the UCM is as good as it gets for that and all in the one box that they can manage instead of the multiple technology manufactures used in this case as above…


Do not disagree and am out of suggestions.


We are all guessing in so far as what the SLC is able to send… in the past I would have been able to quote which program code, sub section pointer to be able to do so … these days… i have to RTFM…

So I am with you … no more thoughts just he needs to sum up the time factor to positive outcome and the solution he should be heading toward to turn it into a positive outcome


The FM was useless on the matter. Oh well. Thanks,


I do it , But No luck


What have you done that has not worked?


set flash range to 800 ( and 900 for test) and Tone Disconnect to y(yes)


I send tick to Grandstream support , he said "enable loop current disconnect (to Yes ) "
I think he wrong .


What about the following:

Panasonic programming/hardware to provide - busy tone for ending of the call on the SLT as a signal to the user to hang up.

This is what is needed from the Panasonic, if it cant then replace the Panasonic with a UCM…otherwise no matter the setting on the Grandstream device, Issabel this will never work


I cant understand.Is it mean Grandstream not work with panasonic?


Panasonic doesn’t work with anything via Panasonic Analogue extensions other than a telephone handset which it was designed to do.


such a question does not make logical sense, what do you mean?
“nothing” works with “nothing” unless properly set.