From: schaefer@alphanet.ch   
      
   Bill Horne  wrote:   
   > I have a vague memory of some requirement that VoIP phone lines support   
   > FAX transmission. I'd like that to be true, but before I go to the   
   > effort of getting my VoIP->POTS adapter to work with Callcentric, I'd   
   > appreciate your help.   
      
   It will be slow and unreliable to transmit fax audio through   
   Voice-over-IP. However, most VoIP adapters have a T.38 settings, and if   
   this supported by your Voice-over-IP provider, it will work [1]: the fax   
   will not be sent through audio but numerically:   
      
   without T.38, slow, unreliable:   
      
   fax machine --- VoIP adapter --- Internet --- VoIP provider   
             analog               numeric audio   
             audio                numeric audio   
      
   with T.38, fast, reliable:   
      
      
   fax machine --- VoIP adapter --- Internet --- VoIP provider   
             analog               T.38 data   
             audio                T.38 data   
      
   After the VoIP provider, you get a standard phone network capable of   
   handling fax audio, where T.38 is converted back. But more problems   
   might happen if the other end is also VoIP without T.38.   
      
   Another alternative would be to sign up with an e-mail to/from fax service   
   provider, there the fax is sent or received as a compressed image.   
      
   [1] https://www.callcentric.com/faq/30#205   
       seems to support receiving fax to e-mail, and has information about   
       T.38 and no T.38.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)