No Dial tone when calling a specific provider Cosmote

[macangelo]

Hello to all!

We have installed 3CX in an On-premise server and we have no dial tone only when calling Cosmote mobile phones. The same issue has been discussed before :

https://www.3cx.com/community/threads/no-ringing-on-some-external-calls.88379/

But nobody has written any answer on this. Any other Greeks having the same problem?

 

[OlegR_3CX]

Hi there.

As it was mentioned in that post if the provider is using 183-Early media and the audio stream is blank, there is nothing 3CX Phonesystem can do here, and you need to speak with your provider.

 

[macangelo]

Hello Oleg
This is the State provider and very difficult to change. Also he has something like 5 million subscribers, so it is very important to have the correct dial tone. So if it is possible with Elastix, would you be willing to make the necessary changes in your software?

 

[OlegR_3CX]

There is no way in our software to manipulate this option and send a different tone to the 3CX application/deskphone and we don't have those options.

 

[macangelo]

Oleg,

when I am calling through another SIP trunk (modulus) to a Cosmote mobile phone I have a dial tone.
when I am calling through Cosmote SIP trunk to a Cosmote mobile phone I do not have a dial tone.

Does this show anything?

Or the outgoing provider is giving the 183 early media , you are referring?

 

[OlegR_3CX]

This is something you can only see in the .pcap file

Or the outgoing provider is giving the 183 early media , you are referring?

This is something you can only see and hear in the .pcap file.
Did you try to talk to your provider so that they could advise you on this and maybe apply the change if possible?

 

[OlegR_3CX]

Once you get to the provider and have some feedback, you could share your experience and if you were able to make the changes on their side.

 

[macangelo]

Cosmote has responded and fixed the issue. I do not know what they did exactly but we now have a dial tone when we call from Cosmote landline to Cosmote mobile.

 

[OlegR_3CX]

Angelo, thank you for the feedback.
Have a great day