Long Continuous Tone Before call starting using 3CX phone for Windows in CTI mode connected to Grandstream GXP2135 IP Phone

[Martino Lombardi]

Hi Everyone,

I’m writing on this forum in order to known if someone has faced and eventually resolved the following issue: using a 3CX phone in CTI mode connected to a Grandstream GXP2135 IP phone, a long continuous tone is generated before call starting.

The used system has the following characteristics:

• 3CX Version: 18.0.1880 Enterprise
• Server OS: Debian 10
• 3CX Server Hosted on Premise
• IP Phone Model/Firmware: GrandStream GXP2135 – firmware version 1.0.11.35
• Provisioning Method: Local
• Trunk Provider and Gateway: Telecom – Gateway: Patton Trinity ISDN BRI (SN4131)
• Firewall Checker Passed: yes
• Custom Phone Template begin used: NO

During our tests, we tried to:

• Reboot and execute a reprovision of the IP phone;
• Use the web client on different browsers (e.g. Chrome, Edge, Firefox);
• Use the Windows App on different PC models;
• Execute a reboot of the 3CX server.

But none of these attempts changed the phone behavior.

Instead, when we use the 3CX phone for Windows in CTI mode connected to other Grandstream IP phone models (e.g. GRP2613) or with other Fanvil IP phones (e.g. X16), the long continuos tone does not occur before the call starting.

Thanks,
Martino

 

[ChrisC_3CX]

using a 3CX phone in CTI mode connected to a Grandstream GXP2135 IP phone, a long continuous tone is generated before call starting.

I've actually just tested this with a Grandstream GXP2135 on the latest supported firmware version (1.0.11.35) provisioned as a Local device on a local 3CX PBX running version 18.0.0.1880 but could not reproduce the issue you're reporting. I even tested it on a different 3CX PBX(18.0.0.1880) hosted with a hosting provider and having the device provisioned via the 3CX SBC but still got the same results.

The device immediately starts ringing once the call is placed via the 3CX Windows App. Is this perhaps what you are referring to? The ringback heard on the device?

 

[Martino Lombardi]

I've actually just tested this with a Grandstream GXP2135 on the latest supported firmware version (1.0.11.35) provisioned as a Local device on a local 3CX PBX running version 18.0.0.1880 but could not reproduce the issue you're reporting. I even tested it on a different 3CX PBX(18.0.0.1880) hosted with a hosting provider and having the device provisioned via the 3CX SBC but still got the same results.

The device immediately starts ringing once the call is placed via the 3CX Windows App. Is this perhaps what you are referring to? The ringback heard on the device?

Hi Chris,
thanks for your support, but I'm not referring to the ringback. I'm referring to a continuos tone that is audible even when the phone is ringing. This tone stops when from the other side someone responding to the call. I've tried to post also a video, but the forum policy didn't alllow to attach files with extension like .mov or .mp4. But I can send it to you in a private email, if you want to see it.
Thanks,
Martino

 

[ChrisC_3CX]

You could upload it to a location such as GDrive, DropBox, OneDrive, etc and provide me with a link via PM so that I can at least better understand what the situation is.

 

[Martino Lombardi]

You could upload it to a location such as GDrive, DropBox, OneDrive, etc and provide me with a link via PM so that I can at least better understand what the situation is.

The following "One Drive" link will be accessible until 27-AUG-2021:

[DELETED LINK]

I hope it will be usefull.
Thanks,
Martino

 

[ChrisC_3CX]

Just an FYI I've reviewed the video but deleted the link due to it containing sensitive information.

Could you do me a favor and give the following a try:

1. Create a completely new extension and make absolutely no changes to it.
2. Factory reset an affected GXP2135 and provision it using that same extension.
3. Try to reproduce the issue again and let me know what happens.

 

[Martino Lombardi]

Just an FYI I've reviewed the video but deleted the link due to it containing sensitive information.

Could you do me a favor and give the following a try:

1. Create a completely new extension and make absolutely no changes to it.
2. Factory reset an affected GXP2135 and provision it using that same extension.
3. Try to reproduce the issue again and let me know what happens.

Hi,
as suggested we tried to create a brend new extension and we assigned it to the Grandstream GXP2135 IP Phone (after a Factory Reset and a provision). The issue is still present.

Thanks,
Martino

 

[ChrisC_3CX]

@Martino Lombardi

We've actually managed to reproduce the issue after some testing and it seems that this has to do with the device's behavior under certain conditions. We'll look into the matter further to evaluate whether there is anything we can do on our end.

 

[Martino Lombardi]

@Martino Lombardi

We've actually managed to reproduce the issue after some testing and it seems that this has to do with the device's behavior under certain conditions. We'll look into the matter further to evaluate whether there is anything we can do on our end.

thanks for your support.
Martino

 

[Martino Lombardi]

@ChrisC_3CX

FYI we also tried to use another 3CX PBX (18.0.0.1880 Standard) and the behavior doesn't change. Actually we haven't a brend new Grandstream GXP2135 IP phone to use for test purpose, so all your help will be appreciate.

Thanks,
Martino

 

[ChrisC_3CX]

@Martino Lombardi

Just letting you know that we contacted Grandstream regarding this and after looking into the matter they have confirmed that it is indeed an issue. They've informed us that this will be addressed in a future firmware release.

 

[Martino Lombardi]

One more time, thanks for your support.
Martino

 

[Martino Lombardi]

@ChrisC_3CX

I'm writing to know, according to your past experience, what could be the firmware release time from Grandstream and the subsequent integration times with the 3CX framework.
Thanks,
Martino

 

[ChrisC_3CX]

I'm afraid I cannot provide a specific ETA nor an estimation as this is entirely up to the vendor and there are many factors that come into play such as how much of a priority this specific fix is. It goes without saying that once we are provided with an updated firmware or template file we will incorporate it in 3CX's installation as soon as possible.

In the meantime, you could always contact the vendor directly for additional information.

 

[AWS2P]

Probably your best way could be to change phone brand /model to something working fine (not a GS one)