Solved Snom D735 Hold

[precmfg]

Greetings, all. I am trialing 3cx and have been pleased thus far. However, one of my test units is exhibiting an odd and unwanted behavior.

The phone in question is a Snom D735 (routed through a D862). When placing a caller on hold, a dial tone is played over the receiver. Hanging up causes the dial tone to play over the speaker. This goes on until the call is retrieved and eventually concluded.

To be clear, the phone plays an audible dial tone the entire time a call is on hold. The calling party does not hear it, however. Music on hold plays for them as expected.

On the D862, holding a call does not present this behavior and I am fairly certain that it is unintended.

In troubleshooting, I upgraded the D735 to the latest available firmware release (10.1.184.14) but the problem persists.

 

[NicholasP_3CX]

The supported firmware of 3CX for this model of phone is 10.1.175.16

https://www.3cx.com/docs/phone-firmwares/

Try with that firmware. The phones behaviour ultimately is something you might need to contact snom to resolve, but try with the firmware we provide and see.

 

[precmfg]

The supported firmware of 3CX for this model of phone is 10.1.175.16

https://www.3cx.com/docs/phone-firmwares/

Try with that firmware. The phones behaviour ultimately is something you might need to contact snom to resolve, but try with the firmware we provide and see.

Thank you for your quick reply. Unfortunately the behavior is present with 10.1.175.16 as well. That is what prompted me to try the unsupported (but later) firmware. I will pursue this with Snom also but wonder how something so obvious would have been overlooked given that the D735 is not a new device. Plainly, I do not believe this is an issue with 3CX but am hoping someone may see my question here and reply with a fix.

 

[precmfg]

After spending quite a bit of time this morning trying to track down the cause, here it is:

There exists an option on Snom desk phones, turned on by default, which plays a dial tone sound when a call is placed on hold. According to Snom’s documentation:

Turning this setting “on” will play a dial tone when a call is being held, signalling the user that he is able to dial a second number. No dial tone is played when this setting is set to “off”.​

Somewhat un-intuitively, the setting apparently behaves differently between the D735 and D862 that I’m testing. I have verified that manually setting the cw_dialtone option to off works.

Posting this update in case someone else has a similar issue. It is not unique to the D735.

 

[NicholasP_3CX]

Can you check in the IP Phone tab of the user, which language you have set for the phone.

Set the language to English US, save, and reprovision the phone (select the phone in the phones page and click reprovision, no need to reset the phone)

This will take care of it automatically without needing to modify anything on the phone.

 

[precmfg]

Again, thanks for your reply and the pertinent information, Nicholas. I can confirm that switching the language from "English" to "English US" does work and sets "cw_dialtone" to off. I anticipate moving to a paid license if testing continues to go well.