System information
CHAPTER 19
Fax
Have no fear of perfection. You’ll never reach it.
—Salvador Dali
The concept of facsimile transmission has been around for over 100 years, but it was
not until the 1980s that the use of fax machines became essential in business. This
lasted for perhaps two decades. Then the Internet came along, and very shortly after
that, the fax quickly became almost irrelevant.
What Is a Fax?
A fax machine allows a facsimile (copy) of a document to be transmitted across a tel-
ephone line. In the Internet age, this sort of functionality seems useless; however, prior
to ubiquitous Internet access, this was a very useful thing indeed. Fax machines scan
a document into a digital format, transmit the digital information in a manner similar
to that used by an analog modem, and then convert and print the received information
on the other end.
Ways to Handle Faxes in Asterisk
Asterisk offers the ability to both send and receive faxes, but it should be noted that all
Asterisk is doing is the basics of fax transport. This means that providing a complete
experience to your users will require external programs and resources beyond what
Asterisk delivers.
Asterisk Fax can:
• Recognize an incoming fax connection, and negotiate a session
• Store (receive) the incoming fax as a Tagged Image File Format (TIFF) file
• Accept TIFF files in a fax-compatible format
• Transmit TIFF files to another fax machine
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