In this chapter, we first had an overview of how fax works in both traditional PSTN and VoIP. Then we described a T38 protocol, which makes faxing available on packet networks.
We delved into FreeSWITCH mod_spandsp, the module in charge of faxing (and other Digital Signal Processing features). We've seen how to configure the module, and how to receive, detect, and send faxes.
We then looked at the most common fax-related processing, like conversion from and to PDF, and mail attachment. We closed the chapter with hints on how to integrate FreeSWITCH's fax capabilities with workflows and ITSPs.
