Dialogic 6.2 - Manual (Page 239)

Processing Media Using the T.38 Protocol
November 2009 239
While the method of transport is different, IP environments support
the functionality of these elements.
There are two types of devices used to implement T.38: an endpoint
and a T.38-aware gateway. TR1034-based applications form
endpoints. The following diagram shows how they support a likely IP
fax scenario:
The endpoint uses the T.30 protocol to negotiate the connection and
performs the image conversion. The gateway simply passes the fax
between a PSTN and IP connection.
Brooktrout
Fax Server
Receiving
Fax Machine Scaling/
transcoding
T.30 /
V.34
T.30 /
V.34
PSTN
Brooktrout
Fax Server
Receiving
Fax Machine
Endpoint
T.30 /
T.38
T.30 /
T.38
PSTN IP
Gateway