Dialogic 6.2 - Manual (Page 241)

Processing Media Using the T.38 Protocol
November 2009 241
This diagram shows how the protocols work together during the call:
In all cases the application must establish the call first using the IP
call control protocol. The call control protocol is responsible for the
initial call set up and tear down.
Sending and Receiving Faxes
Your application can perform transport independent fax
transmission and reception using the Bfv API fax functions. The
application is unaware of the mode of transport (PSTN or SIP).
Dialogic supports all fax functions for Fax over IP. See Volume 4,
Fax Processing, Bfv API Reference Manual for more information
about Fax functions.
PSTN
End-to-end T.30 Protocol management
IP
T.30
protocol
stack
T38
UDP or
TCP
T38
Demodulation
Remodulation
V.17
T.30
protocol
stack