Failing Fax between Grandstream HT801 ATA

[Cascada]

Hi,
Here is the setting:
- 3cx server hosted by AWS
- Customer locations: 2
- Each location has a SBC
- Each location has a ATA HT801 connected to the fax
- SIP provider: Telnyx.

I am able to send and receive faxes to/from anywhere except between the to locations. Every single fax between the two locations fails after 10 ~ 15 seconds. I checked Telnyx and the SIP call is going thru, but for some reason the receiving end closes the connection.

Welcome any input, thoughts, or ideas.

Thank you.

 

[JohnS_3CX]

When site 1 faxes site 2, do you call the DID or the extension directly?

Try sending the Fax Extension to Extension instead and see if that works (ie. do not involve the trunk at all)

 

[Cascada]

Hi JohnS_3cx, great idea, I'll ask the customer to test it. Thank you.