The refer to the following comparison on the differences between a V.90 modem and a V.92 modem:
Comparison of V.90 and V.92 modems:
V.92 support modem has the following charateristics:
1. The communication speed of download (from a provider to a modem) remains at the speed of 56Kbps. This is basically the same as V.90. However, the upload (from the modem to the provider) has improved from 33.6Kbps to 48Kbps.
Note: These speed are theoretical values.
2. The time required for connecting to the provider through the dial-up connection is about 10 seconds (as compared to 20 seconds for V.90). This is due to the reduction of negotiation time and V.92 is able to reduce the waiting time of the next connection.
Basically, the built-in modems of those VAIO computers which are released in and after May 2003 do support V.92.