Phone keeps getting calls from non existant extensions

[Forum User]

I have multiple Yealink phones (model t19p) and all of the sudden some of them are being called and their display shows only a number. It started with number 1 and every new call the number is increased. When they answer the call they get a hangup tone. See attached a photo from one of those calls.

I don't know what this is and how I can stop it. The users cannot do their work anymore and have unplugged their phones to stop them from ringing.
I don't see these calls in the PBX logging. The PBX is version 16.0.3.676

What is this and how do I stop it?

 

[eddv123]

Ghost calls, how often is this occurring and can you trace from the phone(s) (Yealink support this):
http://support.yealink.com/faq/faqInfo?id=320

Also confirm you are running latest templates and firmware, the Yealink T19P models are EOL now so if using this you may want to think about a handset re-fresh: https://www.3cx.com/sip-phones/

This string may help also: https://www.3cx.com/community/threads/ghost-calls.60156/

 

[Alphabetic]

Hi,

Is this phone set up for STUN?

and have you opened port 5060 on your router to this phone?

can you provide more information as requested here https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/

 

[Alphabetic]

PS - i'd just change this setting on your phones.

http://support.yealink.com/faq/faqInfo?id=559

 

[AWS2P]

Could it be wakeup calls ?

 

[BrenttG]

Definitely sounds like you have an opening in your network, and the phones are getting hit from the outside, or by some nefarious device on your network. You quite possibly have some significant security concerns to worry about.