In order to send a long distance fax a 4 digit account code must be entered. This is a carrier service purchased by the customer for accounting. The faxes have worked for years this way. After installing the SPA-2102s It appears that they are not passing the DTMF tones after the connection is made and the carrier sends the second dial tone to challenge for the code.
When we make a test call with the handset on the fax machine we enter the accounting code and after a timeout period the carrier sends the recording that the call can not be completed. We then made a call from a different handset and did not enter the code at all and we got the same recording.
It seems to me that the DTMF codes send through the SPA-2102 from the fax machine would be treated as regular audio and should be passed. What am I missing?
