Strange beaviour (users not being heard) - on premise installation

[GRAT]

Hey,

up front the information of the system:

• 3CX Version, e.g. Standard Annual 16.0.2.910
• Server OS, Debian
• Is the 3CX Server Hosted and where? No, on premise
• IP Phone Make/Model/Firmware Yealink T57W and Android Client
• Provisioning Method: Local / VPN / STUN / SBC Local
• Trunk Provider or Gateway Make/Model Beronet ISDN for incoming Calls, Magenta (Austrian SIP Trunk) fo incoming calls
• Has the Firewall Checker passed: YES
• Are custom Phone Templates being used: NO

The strange behaviour described below occurs with inbound AND outbound calls.

When an agent dials a number or gets an inbound call, the agent cannot be heard by the "outside" party of the call, but the outside party is being understood loud and clearly.

When the call is re-initiated (either from the inside or the outside) everything works fine.

The strange thing ist, that this behaviour occurs only with a handfull of calls - eg we had a total of about 1200 calls on the system yesterday and I got about 10 alerts from agents that the phenomenon occured.

This started about 10 workdays ago, I am not aware of any adjustments to the firewall or the network.

Maybe someone can point me in the right direction or has an idea, where I could start looking.

I know that this is an extremely broad request but so far I have checked all the boxes that I am aware of and I am open to any suggestion.

Due to the unspecific behviour I was also not able to find a thread in the forums matching the topic.

Thanks in advance,

GRAT

 

[JohnS_3CX]

Hi GRAT

Firstly I highly recommend upgrading as soon as possible before you go ahead to troubleshoot, to avoid chasing issues that may have already been corrected with updates.

If for whatever reason this issue still continues after the update, then there are ways of further troubleshooting we can look into.

One thing to look out for though in the meantime: do you face the issue only with beronet or only with Magenta? Or perhaps is with calls from both trunks? And how about internal calls, do they always work well or do they also sometimes have no audio?

 

[GRAT]

Hi JohnS,

thank you for your reply.

Regarding the mentioned upgrade: according to the update function in the pbx I am running the most recent version - did I miss something?

I face the issue with beronet and magenta.

Internal calls are not effected.

We now have a new hint: the admin in charge of the main router activated qos (not directly related to SIP) for a certain service. We deactivated qos alltogether at 12:30 today and so far we had no problems anymore.

I will monitor this closely - anyways, please let me know which upgrade you were referring to.

Best regards,

GRAT

 

[JohnS_3CX]

Hi GRAT,

The QoS thing might indeed be related, especially if it enables any type of ALG features on the firewall that might affect VoIP traffic.

Regarding your update, its seems the PBX is not seeing the updates for some reason. Feel free to send me a private message with your key and I can check to see if I can provide assistance.

 

[AWS2P]

Regarding the mentioned upgrade: according to the update function in the pbx I am running the most recent version - did I miss something?

you inform us about that version

• 3CX Version, e.g. Standard Annual 16.0.2.910

For sure if you did right pasting this info , then for sure your pbx is missing lots of update as we are now running 16.0.1078

 

[GRAT]

Hey guys,

thank you for your replies.

I made a mistake: the 16.0.2.910 came from the thread were the sample information is stated.

I copied our version (which is the up to date 16.0.1078) but did not paste it in the new thread.

Sorry for the confusion,

best regards,

GRAT

 

[JohnS_3CX]

No problem, monitor the system for a few days and if the issue returns let us know.