>I don't know what to tell you, except that we are able to connect at 52K. Sometimes, it is 48, or 42. I have heard that you cannot always trust the numbers. However, all I can say is that performances has been fine for us...

If you connect to an ISP, rather than directly to another ordinary V.90 modem, you'll get downloads at rates up to ~52K (while V.90 allows for rates up to 56Kbps, the telco and FTC impose limits on band usage that limit things to 52-53K max) but uploads will never exceed the 33.6 Kbps rate - in fact, the uplink on a V.90 connection is limited to around 31.2Kbps.

If two V.90 modems connect, it's their relative uplink capabiliteis that set the limit. IOW, while either could receive a 56Kbps stream, neither can send a 56Kbps stream, so the modem connections are limited by the best rates both modems can send at. In most cases (both the Rockwell chipset and the USR/3COM chipset do this), the modem will sense that it hasn't connected to a server modem and will negotiate the best symmetrical protocol available - normally, this means V.34 protocols, symmetrical rates of 33.6Kbps on a perfect line, or lower rates if the noise and signal attenuation won't permit optimal performance.

USR/3COM actually has a reasonably cogent discussion of this on their web page.