X2

1. X2 is a modem transmission scheme developed by UsRobotics (3COM) that is capable of achieving line speeds up to 56 Kbps. This is done by schemes such as V.42bis, to further increase throughput. Because of the two conflicting standards of X2 and KFlex, a standard known as V.90 was developed to converge the two standards into one.
   
   See our modem standard page for additional information about X2 and other technologies.
    
2. X2 is also sometimes an abbreviation used for the Microsoft XBox 2.

Also see: KFlex, Modem definitions, Standard, V.90, Xbox