Two phones out of 16 without VOICE audio

[Cascada]

Hi all,
I got a customer with a strange issue. The customer has 16 phones, out of the 16 phones 2 of them do not have audio-voice (neither out nor in). Let me elaborate a little bit, I pick-up the handset and place a call; I'm able to listen the phone ringing, but once the connection is established, I have no audio. I moved the phones to another location and the phones are working fine, so, I concluded that it is a network related issue, however, all the phones are on the same network.

Here is my configuration
Hosting: AWS
Phones are connected using SBC
3CX version: v18 r4


Any suggestion? Thank you

 

[GeorgeK_3CX]

Hello @Cascada,

You mentioned that when you moved the phones to another location in the same network the issue was resolved. Did you use the same extension numbers for the test? Also are the phones on different network switches which might cause the issue?

 

[Cascada]

Hi, we found the issue. The router had two network segment and they were "on stick." We blocked communcation between the ports... issue solved. Thank you.