User's Guide for ZyXEL Omni 56K USB Modem
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3.3.3 Fax Function
Fax Physical Layer Protocol
Table 8. Fax Physical Layer Capacity
STANDARD BIT RATE
[bps] BAUD RATE
[baud] MODULATION CARRIER FREQUENCY
[Hz]
V.17 14400-7200 2400 TCM 1800
V.29 9600-4800 2400 QAM/DPSK 1700
V.27ter 4800-2400 1600/1200 PSK/DPSK 1800
EIA (Electronic Industries Association) Class 1/Class 2/Class 2.0 Command Set
Please refer to Fax Command Set in Chapter 5.
ITU-T T.30 Fax Protocol
The ITU-T T.30 fax protocol is known as the G3 fax handshake signals and procedures. The
modem takes full control of this protocol – initiating and terminating fax calls, managing the
communication session, and transporting the image data. Therefore, the modem relieves the
computer fax software of the T.30 protocol handling.
Your modem allows for fax speeds up to 14400 bps when transmitting to a fax machine which
complies with the V.17 fax standard. Speeds fall back to 12000, 9600, or 7200 bps in poor line
conditions. When connecting to a G3 fax device, your modem allows for fax speeds up to 9600
bps and automatically falls back to 7200, 4800, and 2400 bps if the line quality is poor.
3.3.4 Voice Function
Voice capability stands for the modem’s ability to digitize incoming voice messages, which
the computer stores and forwards. It also means that the modem playback the recorded
digitized voice on line for a message announcement.
Voice IS-101 Command Set
Please refer to the Voice command sets in Chapter 5.