Faxing is here to stay. Let's admit it: however much we VoIP practitioners hate fax, however much frustration we feel, most of us must deal with fax transmission. Fax is a way to transmit images via voice circuits that were not designed to work on packet networks, and is inherently difficult to implement reliably over VoIP.
T38 is a standard that mediates between SIP and fax to achieve a reliable transmission, trying to overcoming network induced problems. FreeSWITCH implements world-class T38 (and T30, traditional fax) support, and is widely used to serve from occasional to very high traffic fax communication.
In this chapter, we will cover:
How traditional fax works on PSTN
How fax works on VoIP
How to configure and operate FreeSWITCH for faxing
Tips, tricks, and caveats to achieve workflow integration, max success rate, and fax Nirvana