issue with incoming calls suddenly

[a9]

all of a sudden there is an issue with incoming calls on my 3cx instance

the event seen to happen as follows

Incoming Call is placed by Callee then almost immediately they hear a constant Tone for 5-10 seconds before the call is ended

At the extensions side (01) the incoming call rings on the phone as normal if the call is answered it dies if it isn't it also dies

 

[AWS2P]

Hi,

- What is your 3CX version running ?

- 3CX firewall checker passes green ? (if Not, SIP ALG disabled ?)

- is 3CX on premise, cloud hosted?

- Do you use a VPN (only if cloud hosted) ?

- is it Windows, Debian, Pi hardware ?

- Are the phones local extensions on same LAN, or STUN,SBC if remote ?

- What are phones model and brand?

- do you use up to date FW and 3CX standard templates?

- Problem is on one phone or all ?

 

[a9]

Hi aws2p

Version is

Firewall check has passed

3CX is hosted on OWH

No VPN Network is flat

Running on Debian

Phones are on the same network and are provision using STUN

Yealink T21P E2

Firmware is up to date and manged by 3cx

problem is with all Ive changed the call flow and tried direct to several different extensions they all act the same way

Problem is only with picking up incoming call. Outbound works fine

Any help you can provide on this would be of great help

 

[AWS2P]

Version 3CX IS?
is it a new install and it never worked fine, or was it working and now no more?
If it was working previously, did you do some settings changes?

 

[a9]

The version is 16.0.1581

i've not changed anything in over a month the issue just happened today

 

[AWS2P]

this is not up to date, running latest should be 16.0.2.910, do you have updates not applied?

 

[leejor]

And what does the 3CX Activity Log show for one of these incoming calls?

 

[a9]

I have just Ran the update and brought the system up to 16.0.910

the issue has remains the same

I Dont auto update as it has broken systems in the past

 

[leejor]

Do you use DIDs? If so, do you have numbers that route so something other than a DID, receptionist, ring group, queue? Do these calls behave the same?

 

[a9]

the customer has only one main number going direct to a reception extension
it is a very basic layout with only 5 extensions

 

[leejor]

As I said...check the Activity Log, to see if there is anything unusual, for one of the calls.

 

[leejor]

I'm assuming that internal calls to the same destination are working correctly? Have you spoken to the provider, to see if they have made any changes?

 

[AWS2P]

now you are up to date on 3CX side, is the T21P E2 always in latest FW and template?

 

[YiannisH_3CX]

Hello @a9

As a test setup a digital receptionist and have it play a prompt. Then set the inbound rule to that digital receptionist. Call the number and see if the call is answered normally by the system and if you can hear the prompt. This will help you understand if the issue is between the provider and the system or between the system and the phones.
You could also use wireshark to run a capture and see the call flow.