Technical Specifications

Dial-up modems typically have a maximum theoretical speed of 56 kbit/s (using the V.92 protocol), although in most cases only up to 53 kbit/s is possible due to overhead and FCC regulation. These speeds are the maximum possible; in almost all cases transfer speeds will be lower, averaging about 32 kbit/s. Other factors such as line noise further reduce achieved transfer rates. Dial-up connections usually have high latency that can be as high as 200 ms or even more, which can make online gaming or videoconferencing near impossible. Some games, such as Star Wars: Galaxies and The Sims Online are capable of running on 56 K dial-up. Gamers with dial-up connections are often disconnected from game servers due to the "lag", or high latency, of the connection.
If you are a gamer, we obviously recommend broadband.

To avoid incurrent telephone charges always make sure you use a local phone number. Many ISPs offer thousands of dialup numbers, so that in most case you are simply dialing a local number and will not have additional phone charges.

In the last few years many ISP (dial-up providers) offer accelerators (X3 X5....). This is usually a software layer between your PC and the ISPs servers that will compress certain types of data (HTML, images etc...) in general they work very well.

 

List of CCITT standards:

  • Bell 103M & 212A: Older standards, Bell 103 transmits at 300 bps at 300 baud and 212A transmits at 1200 bps at 600 baud.
  • V.21: Capable of only 300 bps, it is an international standard used mainly outside of the U.S.
  • V.22: Capable of 1200 bps at 600 baud. Used mainly outside the U.S.
  • V.22bis: Used in the U.S. and out, it is capable of 2400 bps at 600 baud.
  • V.23: Used mainly in Europe, it allows the modem to send and receive data at the same time at 75 bps.
  • V.29: A one-way (half-duplex) standard that is used mostly for fax machines. Capable of 9600 bps.
  • V.32: A full-duplex standard capable of 9600 bps at 2400 baud. V.32 modems automatically adjust their transmission speeds based on the quality of the lines.
  • V.32bis: A second version of V.32, it is capable of 14,400 bps. It will also fallback onto V.32 if the phone line is impaired.
  • V.32ter: The third version of V.32, capable of 19,200 bps.
  • V.34: Capable of 28,000 bps or fallback to 24,000 and 19,200. This standard is backwards compatible with V.32 and V.32bis.
  • V.34bis: Capable of 33,600 bps or fallback to 31,200.
  • V.42: Same transfer rate as V.34 but is more reliable because of error correction.
  • V.42bis: A data compression protocol that can enable modems to achieve a data transfer rate of 34,000 bps.
  • V.44: Allows for compression of Web pages at the ISP end and decompression by the V.44-compliant modem, so transmitting the same information requires fewer data packets.
  • V.90: The fastest transmissions standard available for analog transmission, it is capable of 56,000 bps.
  • V.92: Transmits at the same speed as V.90 but offers a reduced handshake time and an on-hold feature.