Fluchtkapsel

At work, I currently face the challenge of finding a Linux softphone I can use with a 3CX PBX.

With sipgate we used Linphone, which worked better than sipgate's Softphone or CLINQ apps. But with 3CX the best I could achieve is registering the softphone. With Linphone I can initiate calls but as soon as I pick up the connection gets terminated by the remote side again (at least that's what Linphone says).

I tried Blink, which at least doesn't terminate immediately. But I don't get any sound, on neither end. I can hear recordings originating from the PBX, though. The codec negotiation works, too, as I went through each codec individually.

With Jami and GNOME Calls I can't even register the softphone with the PBX.

#voip #sip #3cx #linphone #blink #jami #gnomeCalls

May 25 at 11:24amWeb
Show threadTakuto May 25

@fluchtkapsel You could try using sngrep on the CLI to look at the actual SIP messages between your softphone and 3CX. That might help you narrow down what the issue might be.

If you have no audio you could look at the SDP within the SIP messages to see if you have matching codecs and / or the IP & Port combinations for the RTP audio streams seem correct.

Show threadFluchtkapselMay 26

@Takuto Thanks for the recommendation. I didn't know sngrep before but, wow, it looks helpful! No further need to work with tcpdump and try to figure out what all that means 😄

I just started working on my issue, so no progress yet. Just wanted to give some feedback and thanks!

Show threadTakuto May 26
@fluchtkapsel Glad to hear that. Feel free to reach out should you need some pointers. I’ll try my best to help.
Show threadFluchtkapselMay 26

@Takuto I could successfully verify that calling my private landline has working audio in both directions using Blink. For comparison I used the browser softphone of 3CX … which didn't had any sound either.

But as the dialpad was just below my GNOME system menu I noticed that my mic was crossed out.

Long story short: Whenever I call my mobile audio input and output gets muted. That's not happening for my landline. Amazingly that happens for both the browser and Blink.

Show threadFluchtkapselMay 26

@Takuto The cause wasn't that obvious after all.

In desperation I called my wife's mobile number and had no issues. That made me look around for causes on my own setup.

My smartphone and my laptop are connected with KDE Connect / GSConnect. The latter is configured to pause media, mute sound and mic whenever I take a call on my phone. And that's what happened.

At the moment I have 2 working options: Linphone and Blink, and I'm fine with that. I'd love to get Calls and Jami working, but that isn't important at the moment.

Show threadTakuto May 26
@fluchtkapsel Oh wow 🤯. I am glad you managed to figure this out. That is a really mean trap to fall into 🙄