Intel LAN+Modem56 PC Card PRO/100 - Manual (Page 153)

Modem Reference 6-29
by AT\Tn. Values are 0-255. Default is 0 (disabled).
S34 DTE Throughput Limit
This register specifies whether the modem should limit throughput
when the DTE is operating at higher speeds (57,600 or 115,200bps)
S34=0
Do not limit throughput (default).
S34=1 Limit throughput to DTE speed.
S35 Data Calling Tone
This register enables or disables a tone of a certain frequency and
cadence as specified in V.25 that allows remote data/fax/voice
discrimination. It is set by AT-Cn. The frequency is 1300 Hz with a
cadence of 0.5 seconds on and 2 seconds off. The default is
country-specific. Some countries do not allow data calling tone to be
overridden.
S35=0 Data calling tone disabled (default)
S35=1 Data calling tone enabled
S36 Negotiation Fallback
This register specifies the action to be taken in the event of a
negotiation failure when error control is selected.
S36=0,2
Hang up
S36=1,3 Fall back to an asynchronous connection
S36=4,6 Attempt MNP. If MNP fails, hang up.
S36=5,7 Attempt MNP. If MNP fails, fall back to asynchronous
connection. Default is 7.
S37 Dial Line Rate
S37=0 Maximum modem speed (default)
S37=1 Reserved
S37=2 1200/75bps
S37=3 300bps
S37=4 Reserved