3Com 3C421600A, Management Manual

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142 C
HAPTER
10: A
DVANCED
M
ODEM
C
ONFIGURATION WITH
CLI/AT
COMMANDS
Understanding Base Rates and True Rates
The x2 speeds listed in the &U and &N table are base rates. From each
base rate an additional 6 true rates can be derived. There are 30 true
rates. The same x2 true rate could be derived from multiple base rates. It
is possible to get an x2 connection at a true rate that is less than the
minimum rate implied by the &U value.
Controlling the Minimum Low-speed Direction
Low-speed direction speed is the send/receive baud rate of the slowest
end of a connection. Use the following S74 settings in Table 36 to control
the minimum low-speed direction speed:
Table 36 S74 Lower Limit Link Speeds
Lower Limit Link Speed Setting Example
No lower limit 0 ATS74=0
2400 1 ATS74=1
4800 2 ATS74=2
7200 3 ATS74=3
9600 4 ATS74=4
12000 5 ATS74=5
14400 6 ATS74=6
16800 7 ATS74=7
19200 8 ATS74=8
21600 9 ATS74=9
24000 10 ATS74=10
26400 11 ATS74=11
28800 12 ATS74=12
31200 13 ATS74=13
33600 14 ATS74=14