A technology developed by Lucent Technologies and Rockwell International for delivering data rates
up to 56 Kbps
over plain old telephone service (POTS)
. It was long believed that the maximum data transmission rate over copper telephone wires was 33.6 Kbps, but K56flex achieves higher rates by taking advantage of the fact that most phone switching stations are connected by high-speed digital
lines. K56flex bypasses the normal digital-to-analog conversion and sends the digital data over the telephone wires directly to your modem
where it is decoded.
Lucent and Rockwell have announced that future K56flex modems will conform to the new V.90 standard approved by the ITU. And users with older K56flex modems may upgrade their modems to support V.90.
While K56flex offers faster Internet access than normal modems, there are several caveats to using an K56flex modem:
1. The high speeds are available only with downstream traffic (e.g., data sent to your computer). Upstream traffic is delivered using normal techniques, with a maximum speed of 33.6 Kbps.
2. To connect to the Internet at K56flex speeds, your Internet Service Provider (ISP) must have a modem at the other end that supports V.90.
3. Even if your ISP supports V.90, you might not achieve maximum transmission rates due to noisy lines.