No ringback tone when calling to a phone line that have A PBX that rings

[krz]

Hi

I just notice that when I call to an office and they have an answering machine for some reason I got no ringback tone, the line will be completely silent until someone pickups the phone

I also had the same scenario calling to place that they have an old analog PBX

My gateway is a Grandstream HT813 I unchecking uncheking PBX Delivers Audio but didnt make any difference also i tried changing the RX gain but no luck so far

any help will be great

 

[JohnS_3CX]

Hi krz

Is this any different when you dial using the webclient / desktop client / or IP deskphone instead of calling from your HT813?

 

[eddv123]

It's more of a setting that you require for PSTN gateway devices such as FXO/ISDN boxes but you issue does sound similar to problems related to early media settings (called early disconnect also sometimes).

 

[krz]

Hi krz

Is this any different when you dial using the webclient / desktop client / or IP deskphone instead of calling from your HT813?

The HT813 is a FXOgate and I have tried using using webclient desktop client and ios app and the same results

 

[JohnS_3CX]

Ok so when you make a call outside the PBX, it has to pass through the provider. They will either tell your PBX to play ringback (in which case your phone or ATA should generate the tones) or they will play it in the audio stream and you will see an RTP stream coming your way while the other side's phone is ringing.

There's also the possibility that the other side was already answered by their PBX and its not playing their internal ringback / music on hold to you so you hear the silence from their PBX until their internal call is picked up (this is probably what happened in your case).

I think you should run a capture while calling that destination and then analyze it in wireshark to confirm it.

 

[krz]

I am not sure if this is the actual solution but is working now fine

In the HT813 under advanced settings fill where it said "Config Server Path:"

this information is found on the 3cx gateway configuration