ZyXEL Communications U-336R, User Manual

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54 Fax Operation
ITU-T T.30 Fax Protocol
The U-336R/RE takes full control of the ITU-T T.30 fax protocol,
also known as G3 fax handshaking signals and procedures. Your
modem initiates and terminates fax calls, manages communications
sessions, and transports image data relieving the computer fax
software of the T.30 protocol handling.
You modem allows for fax speeds up to 14400 bps when
transmitting to a fax machine which complies with the V.17 fax
standard. Speeds will fall back to 12000, 9600, or 7200 bps if poor
line conditions are encountered. When connecting to a G3 fax
device, your modem allows for fax speeds up to 9600 bps and will
automatically fall back to 7200, 4800, and 2400 bps if the line
quality is poor.
Fax Command sets
Your modem supports four command sets for fax operation:
•
Class 1 command set.
•
TIA PN-2388 Class 2 command set.
•
TIA 592 Class 2.0 command set.
•
ZyXEL Extended Fax AT command set.
Defining the Fax Command Sets
The EIA Class 1 and Class 2 fax commands are a set of AT fax
commands defined by EIA/TIA (Telecommunications Industry
Association) for controlling fax/modems from a computer through
the serial RS-232 interface. All fax/modems and fax software
supporting this standard will be compatible with each other.