| Appendix |
Fallback | In adverse line conditions, the modem falls |
| back from its current operating speed to the |
| next reliable slower speed in 2400 bps |
| decrements (V.34 mode). If conditions |
| improve, the modem falls forward to the |
| fastest reliable speed in 2400 bps increments. |
| In V.90/K56flex mode, modem falls back and |
| falls forward in increments of 2000 bps. |
Modes of Operation | |
| automatic dialing, automatic or manual |
| answer. |
Flow Control | Software (XON/XOFF), hardware (RTS/CTS) |
Intelligent Features | Fully AT command compatible, autodial, |
| redial, pulse or tone dial, dial pauses, call |
| status display, |
| selection, |
| options, and nonvolatile memory and on- |
| screen displays for modem parameters. |
Command Buffer | 40 characters |
Data Modulations | FSK at 300 bps, DPSK at 1200 bps, QAM at |
| 2400, 4800, and 9600 bps |
| with |
| 12,000, 14,400, 16,800, 19,200, 21,600, |
| 24,000, 26,400, 28,800, 31,200, 33,600 and |
| 56,000 bps |
Fax Modulations | V.21 CH2: FSK at 300 bps |
| V.27ter: DPSK at 4800 and 2400 bps |
| V.29: QAM at 9600 and 7200 bps |
| V.17: TCM at 14400, 12000, 9600, and 7200 |
| bps |
Carrier Frequencies: | 1600, 1646, 1680, 1800, 1829, 1867, |
V.34/V.90/K56flex | 1920, 1959, 2000 Hz |
Carrier Frequencies: | 1800 Hz |
77 |