ALERT

[WEBINAR] See the Whole Story: The Case for a Visualization Platform

X2

Definition - What does X2 mean?

X2 was a modem protocol developed by U.S. Robotics (now 3Com) to download data at 56 Kbps under pulse-code modulation without the need for modulation/demodulation. It used V.34+ to upload data at 33.6 Kbps using plain old telephone service lines.

X2 was replaced by the V.90 standard, which combines both X2 by U.S. Robotics and K56flex from Rockwell Semiconductor.

Techopedia explains X2

The X2 modem protocol overcame the long-held belief that 33.6 Kbps was the fastest data transmission rate possible over copper wires. Knowing that most phone switching stations were connected by high-speed digital lines, X2 eliminated the need to modulate/demodulate digital data using an analog carrier signal. As a result, the normal modulate/demodulate process was eliminated, allowing for a faster data transfer rate. If the Internet service provider (ISP) had a digital connection to its telephone office, the X2 modem now only had to decode the multibit voltage pulses, just as the telephone lines were designed to do originally.

However, X2 had some stipulations along with the higher downstream transfer rate:

  • The upstream data transfer remained at 33.6 Kbps with a maximum possible rate of 40 Kbps
  • The ISP had to provide a modem that supported V.90 at the originating end of the transfer
  • Noisy lines resulting from interference from other phone lines could reduce the maximum possible transmission rate

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
"Techopedia" on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!

Email Newsletter

Join thousands of others with our weekly newsletter

Resources
Free Whitepaper: The Path to Hybrid Cloud
Free Whitepaper: The Path to Hybrid Cloud:
The Path to Hybrid Cloud: Intelligent Bursting To Amazon Web Services & Microsoft Azure
Free E-Book: Public Cloud Guide
Free E-Book: Public Cloud Guide:
This white paper is for leaders of Operations, Engineering, or Infrastructure teams who are creating or executing an IT roadmap.
Free Tool: Virtual Health Monitor
Free Tool: Virtual Health Monitor:
Virtual Health Monitor is a free virtualization monitoring and reporting tool for VMware, Hyper-V, RHEV, and XenServer environments.
Free 30 Day Trial – Turbonomic
Free 30 Day Trial – Turbonomic:
Turbonomic delivers an autonomic platform where virtual and cloud environments self-manage in real-time to assure application performance.