I am trying to install a GrandStream HT701 ATA via Sip connection to a TDE 600. Customer needs fax service to an office a 1/4 mile away connected via fiber (no copper).The ATA is registered to the PBX and incoming calls (internal and DID) work great. The problem I am having is when attempting outgoing calls (internal or outside)the system returns a fast busy, as if the TDE-600 is rejecting the attempt. I have gone over the ATA dial plan and settings with GrandStream to no avail. Any suggestions or successes you have had with other models of ATA's would be appreciated.
Thanks,
Fred
Thanks,
Fred