Configuring The V.120 Mode - ZyXEL Communications Omni TA128 User Manual

support out-of-band signaling, network signals are transmitted
through the B channels. This reduces the bandwidth to 56Kbps.
When you are making a V.120 call, make sure that the
communication supports out-of-band signaling. If it does not support
out-of-band signaling, you will need to set your TA128 to 56K mode
using the AT&E1 command (AT&E0 to set it back to 64k mode.) If
your TA128 is on the receiving end, you can keep the setting at
AT&E0, 64k data mode. The TA128 will automatically switch
between the two speeds in answer mode.

Configuring the V.120 mode

To configure for a 56K V.120 call, type:
ATB20<Enter> (Select V.120 for communication)
TA128 responds:
OK
Type:
AT&E1<Enter> (Select 56K data mode)
TA128 responds:
OK
Now you are ready to dial the phone number. If you need to save the
setting into non-volatile RAM, issue the commands:
Type:
AT&W0<Enter> (Save the settings to profile 0) [Profiles available: 0-3]
TA128 responds:
OK
Type:
ATZ0<Enter> (Save stored settings as the power on settings to profile 0)
[Profiles available: 0-3]
TA128 responds:
OK
50