3CX Webclient / Dialing out / Hear dial tone + ringback at the same time

[fgc92210]

Hi,

3CX Pro 16.0.6.655 @ Debian.
GrandStream GXP2170 is my desk phone.
I am using the webclient to make tests. If I select someone from the phone list, or call someone with a prefix + number in the web client (which is setup to use Deskphone), then my Deskphone goes hands free which is expected, but I hear both dial tone + ringback at the same time, until the third party picks up the phone.

Any way to fix this?

 

[JohnS_3CX]

Hi,

Simplify, don't use the webclient at all in this test.

If you dial directly from your 2170 do you experience the same issue?

I'm guessing that this is happening specifically when you dial external lines and not when calling internal extensions.

 

[fgc92210]

Hi John,
I was able to reproduce this multiple times on the day it happened.
I was like that before I created this post. 3CX did not reboot since then. I just try again this morning, and the issue is not here anymore. I guess we can close this topic..

 

[JohnS_3CX]

No problem, but in case the issue comes back then I would recommend to make a call directly from the phone (do not use webclient) and see if you hear both tones at the same time.

Your trunk might not have "PBX Delivers Audio" enabled, and there cases where the provider will send you the ringback. It's not clear if that will lead you to hearing 2 tones but I suppose there is some possibility. Enable the above option in that case and notice if the problem goes away.

 

[fgc92210]

Hi John,

Calls from the phone directly worked the whole time.
It were just those instances where I used the web interface to call back missed calls.

I also checked the trunk (Flowroute), and I can see that PBX Delivers Audio is checked. Not something I changed as it was a default value...

I will make tests again in the next couple of days and will update this thread.

 

[JohnS_3CX]

Thanks, let us know how it goes and we can look further into it as needed

 

[fgc92210]

Hi John,

Randomly was able to reproduce this error.
Went to my Web SoftPhone (macOS, Chrome), selected Browser extension to place a call, switched back to GrandStream GXP2170, from the web interface entered my trunk seizure prefix + number , then my Deskphone goes handsfree and has dial tone + ringback tone.

Any type of traces you want me to run?

 

[fgc92210]

I ran a tcpdump on the 3cx, and could not hear the ring tone being played in the call flow. I'm going to port mirror the port where the phone is connected, and do a tcpdump also to see if I hear this. If I do not, I would assume it's played from the phone directly and might be another issue with with SIP Packet request from 3CX to the phone ?

 

[fgc92210]

John,
Nothing in the SIP Flow that plays the dial tone.
So somehow, when the phone picks up, it plays both the internal dial tone, and external ringback tone sent from the PBX.

I'm going to see if I can send <MakeCall> xml packets to the phone and reproduce this way.

 

[fgc92210]

John,
I use sipP as a sip packet generator, but I cant compile it on the new computer I am on now. I dont have time to troubleshoot, but will keep this in my todo list for later this month. If you have any idea at the same time, I'll take them. thank you.

 

[JohnS_3CX]

Hello,

Those were some good tests, based on what you found it appears to be a device specific behavior when making calls using CSTA mode (remote controlled by webclient).

I will try and see if I can replicate it here too, but please tell me the following:

• GXP2170 Firmware Version: ?
• Provisioning method: LAN/SBC/STUN ?
• Using modified templates or default?

 

[fgc92210]

Hi,

GXP2170 firmware version 1.0.11.16
Provisioned through STUN, without SBC
Default template

As of this morning, I still have the issue.
System was "rebooted" over the week end since I moved 3CX from AWS to DG.
Let me know if there is any special tests you want me to run on the phone before I reboot it. I will try again with the sipp in a few hours, if I remember how to generate SIP packets. If you have any other sip packet generator you can recommend, I'll take it. Thanks !

 

[fgc92210]

I was able to reproduce this on other GrandStream.
I added a SNOM to my profile (same configuration, STUN, no SBC), and can't reproduce the issue on this phone using the same scenario.

 

[JohnS_3CX]

It's beginning to sound more like a Grandstream issue, but I wasn't able to replicate it on mine so far.

It may depend on your provider perhaps sending a 183 with SDP, and possibly the phone plays that AND also plays its own.

If you can take a capture on the phone itself, we might be able to get a better picture

 

[fgc92210]

Hi,
From the trace between 3cx <-> phone, I see a 183 Session in progress

 

[JohnS_3CX]

ok, that makes sense, and if you also hear the RTP stream in the capture do you hear an audible progress tone?

 

[fgc92210]

Hi,
No progress tone in the capture.
Hence why I thought it came from the phone directly.

 

[JohnS_3CX]

Ok that's an important point, which seems to suggest the phone itself may indeed be doing this.

I think it's wise to replicate this using a factory reset phone, with a clean extension, and without changing any of the defaults so we can get a baseline of how the device behaves.

 

[fgc92210]

Hi John,

Sorry for the delay. I tried to install the GXP2170 on a brand new extension, and I have the same issue. Dialtone heard while ringback tone is playing.

Factory reset GXP2170 V1.0.11.16 setup as direct STUN, no SBC
3CX Pro 16.0.6.655