Dialogic 6.2 - Manual (Page 238)

Processing Media Using the T.38 Protocol
November 2009 238
Processing Media Using the T.38 Protocol
The Brooktrout SDK supports real-time sending and receiving faxes
over IP following the T.38 protocol for exchanging messages and
data through IP fax gateways or IAF devices over an IP network.
Because Brooktrout’s Bfv Call Control API uniformly supports a
wide set of transports including IP, you can use the same fax
functions for fax over IP as when sending faxes over the PSTN. You
can configure your system using the Brooktrout Configuration Tool
(a GUI product) or by editing user-defined files.
Using standard fax machines over the PSTN, the following
information is presented.
„ The sender of a fax gets immediate notification of a fax being
sent successfully.
„ The receiver gets information on the sender’s telephone number
and the time the fax was received.
Bfv’s IP fax support provides this information as well.
Traditionally, faxing has been done over the TDM telephone
network, as defined in the ITU specification T.30. In a traditional
PSTN based T.30-only fax transmission, sending a fax requires three
fax components:
T.30 Protocol Engine
While T.30 is a mature technology, an effective T.30 implementation
is complex due in large part to the challenge of connecting with the
installed base of 120 million fax machines whose own compliance to
the standard varies considerably.
Image Conversion Engine
The sending device must adapt (scale and transcode) the image to
the capabilities of the receiver. The receiver must check the received
file for errors and try to correct ones that occur.
Modem
This is the vehicle to carry the protocol and image data across the
PSTN network.