ZyXEL Communications U-336R/RE manual Fax Command sets, ITU-T T.30 Fax Protocol, 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.

54 Fax Operation