[Freeswitch-users] fax tone testing

Hi I suspect that my telco set-up is acting funny and I want to use spectral analysis to confirm the culprit :) What is the best way to generate Fax tones from a dialplan and then record them at the other end? Also, where can I get a list of the all the tones and duration which are used in Fax. Thanks. regards, Anita