BLF Issues

[kfjelsted]

I am encountering an issue with BLF on a Yealink phone. When the BLF is associated with an extension that has a 3CX device config for a Cyberdata, it functions correctly. However, when the BLF is associated with an extension that has registered a generic FXS, the BLF does not show the status of the call and I am unable to answer incoming calls to that extension via the BLF. The same BLF works perfectly fine on a 3CX Windows softphone, both showing the status and allowing me to pick up incoming calls. How can I resolve this issue?

 

[JohnS_3CX]

However, when the BLF is associated with an extension that has registered a generic FXS

Do you mean that the extension is not assigned to any FXS or IP phones in 3CX, you simply just used the credentials to register a unsupported FXS model for example?

Also a lot of specifics are missing:

- Yealink Model number
- Yealink Firmware number
- BLF type is actually "BLF" and not Speed Dial / Custom Speed dial
- If the BLF is actually green before the FXS is called
- What happens when the BLF is pressed
- What FXS it is..

 

[kfjelsted]

Extension A has a SIP-T46S Yealink phone (firmware 66.86.0.5). The BLF is set to the BLF type both in 3CX and on the device management platform. Extension B has an FXS device that adheres to standard SIP protocol, including early media.

Prior to receiving an incoming call to B, the BLF on A's Yealink phone is green. When B does receive an incoming call, the status light does not change. When A tries to answer B's incoming call using the BLF button on their Yealink phone, it places a new call to B instead of answering the B's incoming call.

This issue is only occurring on the Yealink however. When we test with the 3CX Windows Softphone for example the BLF shows the correct status and is able to answer B's incoming call without issue.

 

[JohnS_3CX]

Thanks, it's a good sign that the BLF is green, let's also look at some other details now:

- Version number of 3CX?
- How is the Yealink connecting to 3CX: local on same network, STUN, or SBC?

PS: you can upgrade the phone, version 66.86.0.15 has been out a long time now

 

[kfjelsted]

The 3CX is running in Google Cloud and the version is 20.0 Update 3 (Build 806 Release), and the Yealink is connecting to 3CX by SBC.

 

[kfjelsted]

Through additional testing, we think this may be caused by extension B working with a non-defined or generic device. Before, when we used our CyberData FXS device, it worked without issue but it also had a device template. How can we clone a device template to customize for our new FXS device that we are using now?

 

[kfjelsted]

In 3CX, how can we force a generic extension to register behind an SBC rather than using a public internet address? We encounter issues when attempting registration with a private address behind the SBC, which is running on Ubuntu in the same private subnet as our other system (Jambonz). However, registration with a public address is successful.

 

[JohnS_3CX]

Our SBC was never designed for nor tested on Ubuntu. You should use follow our guide here to install it as intended
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

To manually register behind our SBC: https://www.3cx.com/docs/manual/ip-phones/#h.gwqg1qvtfjy7

Other than this we cannot provide any further support for generic FXS so if you still have issues with it you will have to troubleshoot everything manually.

 

[kfjelsted]

Our SBC was never designed for nor tested on Ubuntu. You should use follow our guide here to install it as intended
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

To manually register behind our SBC: https://www.3cx.com/docs/manual/ip-phones/#h.gwqg1qvtfjy7

Other than this we cannot provide any further support for generic FXS so if you still have issues with it you will have to troubleshoot everything manually.

I am sorry I don't know what I was thinking we did indeed install using the 3CX ISO per the doc you provided and I should have said Debian! not Ubuntu. Thank you for the clarification on the other docs to follow.