Unsupported 3CX, AWS, Cisco Phones - Suddenly dead (no voice)

[AndWei]

Hello!

Something very strange happened to me....

For over two years, the combination of 3CX + AWS + Cisco Phones (SPA525G2, FW: 7.6.2f) + multiple SIP trunks has been running fine and without any complaints.

A few weeks ago I removed an Amazon Chime phone number from the 3CX configuration and also removed it from the Cisco Phones and disabled Line 5. After that, everything worked as usual.

Now the phone system was not used for a few days due to a reconstruction in the building. Some phones that were still on (powered by PoE) were also lit and showed that they were connected to the 3CX server or that the phones were registered.

Today I powered up all the phones again and mine showed that there was a voicemail for me. So I dialed the voicemail (dial tone there, ring tone there) and as soon as the connection is established, I don't hear anything. But it is displayed that the connection still exists (call duration display). The same with internal calls.

So next "test". Called another (external) number. Exactly the same. Dial tone ok, it rings... as soon as we pick up, nothing more. Almost silence!

There is nothing "suspicious" in the CX logfile. After a few hours, I was so desperate that I installed a second 3CX system (following exactly these instructions: https://www.3cx.com/docs/cloud-pbx-amazon-aws/) to eliminate as many sources of error as possible.

Only one SIP trunk configured, only one phone and even a Cisco SPA112 adapter registered. No error message in the log file, BUT the result is exactly the same!

I did notice that installing 3CX on an AWS server is a bit different, but has anything else changed in the last weeks or months?

I know this all sounds totally weird! :-(
But does anyone have any tips?

Maybe I'm totally blocked right now, but it can't be that even after a fresh reinstallation, the new system behaves exactly like the "old" one!

THANK you, very much!

 

[AndWei]

A little update!

I have entered the access data of a SIP provider both one of the phone, so also in the SPA adapter and then it is immediately possible to establish a call and also to speak.

So this must be somewhere at 3CX or AWS or the combination of both and therefore something must have changed.

 

[leejor]

Dial tone and ringback will originate from the set itself, so it sounds (no pun intended) like the voice packets are not able to get through to the set, or are being misdirected.

Are you using STUN on the set?

You might check the 3CX Activity log to see how the set is registering. What IP is it "telling" 3Cx to reach it at, and what port? Make certain that there are no port conflicts behind your router.

 

[AndWei]

@leejor
Thanks for your input!

Before I go into detail and try to get some more details from the log files, I would like to point out that EVERYTHING was working fine and without a problem a few weeks ago. Nothing was changed in the configurations, neither in 3CX nor in the phones.

And also a second completely new 3CX + AWS installation does not work. Something must have changed in 3CX by an update or something.

I have just re-entered access data from another SIP provider directly on a phone and the SPA adapter. Phone calls immediately possible!

On the phones and on the adapter, stun-us.3cx.com is entered as the STUN server. Nothing has been changed on this either.

 

[cobaltit]

So the SPA phones are not supported remotely with either STUN or SBC, so unless you have a VPN connection to your 3CX AWS instance, this is an unsupported configuration and has been for some time. You are also running an unsupported/untested firmware version although that is probably not an issue. I would start by testing a supported phone or use the webclient/PC/mobile app. If you can make/receive calls from that. If that works, then it's not a 3CX issue.