Toshiba V.92 - Manual (Page 73)

73 AT Commands
AT command formats
5.375 x 8.375 ver 2.4.0
+DS44 V.44 Data Compression Command
This command configures the V.44 data compression
direction used by the modem. It can also be used to display
the current data compression configuration, and the
supported parameter values.
+DS44 =
Valid values are as follows:
5 32000 bps
6 33333 bps
7 34666 bps
8 36000 bps
9 37333 bps
10 38666 bps
11 40000 bps
12 41333 bps
13 42666 bps
14 44000 bps
15 45333 bps
16 46666 bps
17 48000 bps
18 49333 bps
19 50666 bps
20 52000 bps
21 53333 bps
0 Modem does not negotiate V.44 compression.