Paradyne COMSPHERE 3920PLUS Series, Technical Reference Manual

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COMSPHERE 392xPlus Modems
5-56 October 1998 3920-A2-GH30-40
Table 5-10
(4 of 4)
Dial Line Configuration Options — Singleport Mode
A
V.34 Precoder: Disable
Nxt Disable Enable
This configuration option only appears when V.34 is enabled.
V.34 Precoder. Determines whether the V.34 Precoder is used when operating with V.34 family modulation on either dial
or leased lines. The V.34 Precoder can improve performance under certain unusual line conditions, i.e., low harmonic
distortion, single frequency interference.
Disable – Does not use the V.34 Precoder.
Enable – Uses the V.34 Precoder.
The AT command S-register is S27 = n, where n is 0 for Disable and 1 for Enable.
Asymmetric Rate: Enable
End Enable Disable
This configuration option does not appear unless V.34 modulation is selected.
Asymmetric Rate. Controls rate symmetry when running V.34 modulation by enabling or disabling the V.34 modulation
from using equal transmit and receive rates.
Enable – The modem operates in asymmetric rate mode (the transmit and receive rates can be different) when running
V.34 modulation. The Asymmetric Rate configuration option must be enabled in both modems.
Disable – The modem operates in symmetric rate mode (the transmit and receive rates are identical) when running
V.34 modulation. Either modem can force symmetric mode by disabling the Asymmetric Rate configuration option.
The AT command is S-Register S14 = n, where n is 0 for Enable and 1 for Disable.
NOTE: This configuration option is typically disabled when the MUX is in use, and it is enabled when the MUX is disabled.
If you are using a factory template that has the MUX enabled, and then you manually disable the MUX, you must
verify that this configuration option is set to the correct value.
Proact Retrain: Enable
Nxt Enable Disable
Proactive Retrain. When enabled, the dial line connection is monitored, and if the Signal to Noise Ratio drops 1.2 dB or
more, the modem forces a retrain. This may prevent bit errors at higher rates over marginal lines. Disabling Proactive
Retrain reduces the number of retrains while increasing the exposure to bit errors.
NOTE: This configuration option works on dial connections (including dial backup), in synchronous or asynchronous mode,
at 31,200 and 33,600 bps. It has no effect on leased line connections.
Disable – Proactive Retrain is disabled.
Enable – Proactive Retrain is enabled.
The AT command S-register is S23 = n, where n is 0 for Enable and 1 for Disable.