3CX App PWA auto switches from phone to dect

[Alle CTEC]

I have a client using the 3CX PWA application in a Terminal Server environment. The user has an Snom D735 desk phone with a Jabra headset and an Snom M25 DECT cordless handset (paired with an M900 base). The user suddenly called me reporting that they could no longer transfer calls. They use the headset to answer and transfer calls via the application. I noticed—inexplicably—that the PWA application had switched control to the DECT handset. Consequently, when the user answers, the audio comes through the headset (which is odd, as it should be coming from the DECT handset), and subsequently, they are unable to transfer the call. Resetting the phone resolves the issue, and everything works perfectly.

 

[KyriacosS_3CX]

Hello,

Can you please clarify some details, so we can be sure we are reading the post correctly?

The Jabra headset, is it connected to the PC/PWA or to the D735 desk phone?

Resetting the phone; this refers to the D375, correct? A reset is to restart the phone, reprovision the phone, or simply choosing it again in the PWA as the call device?

 

[Alle CTEC]

Hello. The user is working via a remote desktop terminal server using a PWA application. They have an Snom D735 desk phone with a Jabra headset connected via both the headset port and an optional Jabra AUX accessory. The PWA application is not configured as a softphone itself but controls the Snom D735. Since the user also has an Snom M25 DECT handset (with M900 cells), the application inexplicably switches at random to controlling the DECT handset instead of the Snom D735. In this state, the app controls the DECT unit—meaning the call is handled via the DECT handset rather than the desk phone. If I click "Answer," the call is answered on the Snom D735; if I put a call on hold, it works; however, if I try to transfer a call, it fails—instead, a second call starts that is not linked to the original one. Resetting the control setting back to the desk phone restores normal operation.

I assume that, for some reason, communication between the application and the phone is lost, causing the PWA to automatically switch to DECT; however, I do not understand why it continues to work partially on the D735 but not on the DECT.

Thanks

 

[JohnS_3CX]

Too much confusion, let's separate the issues and address them one at a time

1. Headset: lets ignore this because its not connected to 3CX. Unplug it from the phone while you are testing to make life easier as you troubleshoot. You can always add it back later. Otherwise it just adds to the confusion in the description.

2. Transfers: Either user the D735 itself directly or use the client - do NOT press buttons on both during the same call. Choose one or the other and stick with it.

The client's remote control mode has a limited list of functions:
Here hold/unhold is not supported.
So you cannot return to the caller, only these are available during a call:

Otherwise a second call starts that is not linked to the original one.
If you want more flexibility use only the D735 physical phone buttons.

3. Preselected device: Sometimes it will be the M900 and other times it will be the D735. It depends which one registered first. It also depends if one goes offline briefly, the client will switch to your next available device (M900).

Does the specific user need a complex setup with D735 + headset + DECT + client in terminal server?

 

[Alle CTEC]

I performed the following test: I disconnected the headset and set the 3CX PWA application to "Cordless" control mode. When a call comes in and I click "Answer" in the application, the call is answered on the desk phone in speakerphone mode. If I press "Hold," the call is put on hold, but options like call transfer or conference are greyed out and cannot be clicked. When I switch the application setting from DECT to "Desk Phone," the greyed-out transfer and conference options become clickable and fully functional. It is as if the application—even when set to cordless mode—is somehow controlling the desk phone.

The Remote Desktop Server Thin Client user is based at a clinic workstation; therefore, a headset-equipped phone combined with the PWA is an ideal choice—it delivers the necessary application functions via the PWA while maintaining the stability of a standalone phone. The cordless handset is required for mobility. Correct me if I am wrong, but the 3CX Windows Store app cannot be installed in a Remote Desktop environment. Furthermore, Snom solutions like the SP800 are now available; these were not an option at the time of the initial setup, so using a remote headset setup was not a viable approach back then.

 

[JohnS_3CX]

set the 3CX PWA application to "Cordless" control

Hi Alle,

This is a fourth topic: using your cordless phone (such as your M900) in remote control mode.
Unlike desk phones, for DECT devices we don’t support uaCSTA, the protocol we use to control desk phones remotely.

So instead the PBX simulates the functions for you, with a few limitations:

• When you dial a number, your M900 rings first. Once you answer, the PBX connects you to the number you dialled.
• When you end the call, the PBX disconnects your M900.
• You can make a blind transfer.
• Conference calls, hold/resume, and attended transfers aren’t available.

Only this will appear as active:


This gives you remote control of desk phones, plus some control of DECT and FXS devices too.
I hope this helps clarify what you can do with remote control and where the limitations are.

Correct me if I am wrong, but the 3CX Windows Store app cannot be installed in a Remote Desktop environment. Furthermore, Snom solutions like the SP800 are now available; these were not an option at the time of the initial setup, so using a remote headset setup was not a viable approach back then.

• The SP800 has the same limitations and no physical buttons, so it won’t support some of the actions available on the D735. It may not be the best fit for your setup.
• The PWA app also works on Remote Desktop, but routing audio through RDP to the PBX can add some delay. A poor connection can also cause audio issues. This setup works best when the terminal server, users, and PBX are on the same LAN.

I think your current setup works well for your needs. Just let the user know what each device can and can’t do, so they know what to expect in different situations.

 

[Alle CTEC]

That is all very clear; however, my initial question is: why—if I have the 3CX PWA application configured to handle the cordless phone—does clicking the "answer" button result in the call being answered on the desk phone in speakerphone mode?