Incoming Faxes

[limaecho]

Wondering if someone can help solve this.

We have had incoming faxes working without any issues. 3CX Fax server has been setup under settings with DID allocated to it.

Now today the client reports that some of their fax senders have complained that fax is failing. So i looked at the Faxes\failed folder and there have been a lot of faxes that have failed.

This is the error message.
<RCV_ERROR>Disconnected after permitted retries</RCV_ERROR>

Also it mentions the IMGFILE but these files don't exist at all. I couldn't find any other trouble shooting to be done.

I have attached the pcap flow of the call.

 

[StefanW]

From the PCAP it is simple to see that on the fax call the provider never replies to any T38 instructions.

Note: I will relocate the topic into the General Forum

 

[limaecho]

Thanks sorry not a PCAP expert. But much appreciated. I will raise this with our SIP provider.

 

[NikosT_3CX]

@limaecho as I can see from the screenshot :
a) your Provider does not send anything to the PBX after the 200 OK SDP after the ACK of the PBX.
PBX tries to negotiate fax parameters but provider does not send anything back.
You have to speak with your Provider.

b) this is not a 3cx Hosted PBX as your ip address is 172.18.x.x which is a private ip address and this is not hosted on 3cx infrastructure so I think you have posted this to the wrong Category.

 

[limaecho]

Thanks nikosT - much appreciated. Sorry about posting in the wrong section.