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Practical Guide to 56k

...because it doesn't have to be complex.

by Niels Jonker

Copyright © 1997 Niels Jonker

All Rights Reserved

By now, you have most likely heard of a new generation of modems which, according to the ads, will be quite a lot faster than the modems currently available. On this page, we will give you some insight into the approach U.S. Internet has chosen to implement this new strategy. We will also try to explain some of the issues related to this new technology.

Existing Standards and Modems

As you probably know, all modems are standardized. These standards prescribe the speeds at which modems will communicate and the signaling technologies used. The organization that sets these standards is the Telecommunication Section of the International Telecommunication Union, ITU-T in short. Some of the standards that you may be familiar with are:

These standards are very important to you. If you buy a V.34 modem that supports V.42bis compression, you can be assured your modem will work with all other modems that adhere to these standards. Since the ITU-T keeps the standard and will not allow random changes, you know your modem will continue to work correctly with other modems out there.

Emerging Technologies and Standards

Whenever a new technology comes along, it is submitted to the ITU-T for standardization. At that point, a long process starts where every major player in the field gets input on exactly what the standard should and should not say. This process typically takes from one to two years.

Inventors of such new technologies are often not willing and able to wait that long before they introduce the new technology. This is why in general, products are released way before the standard is set. You may remember the introduction of 28.8 modems, where there were at least two 'Non-Standards' released (V.FC, V.Fast) before the final ITU-T standard of V.34 came along.

Some people that invested in pre-standard technology in the 28.8 saga got burned badly; they found out that the V.FC modem they had bought would not work with the standard modems that came out later, and ended up spending more money when the standard was set.

The same thing seems to be happening to analog 56K modems.

The 56K Analog 'Non-Standards'

So far, there are two 'camps' in the 56K Analog Early-deployment Non-Standard War.

One standard is called K56flex. This standard is spearheaded by an industry alliance consisting of many companies, such as Lucent technologies / AT&T, Motorola, Rockwell, Ascend Communications, Cisco, MultiTech, Hayes, Microcom, Compaq, HP, AST, Toshiba, and others.

The other is proposed by U.S. Robotics, the company that was the first to start marketing the new technology about four months before it was available. This standard is known as x2. It is at this time supported by U.S. Robotics and some of the vendors that private label USR products.

The K56flex supporters have made it a goal to be ITU-T compatible as soon as possible. U.S. Robotics will most likely do the same, but has not yet publicly made claims to that effect. The K56flex consortium produces the modem chips used in an estimated 85% of all new modems sold, and about 70% of modems currently installed, a clear majority. An additional twist is the acquisition of U.S. Robotics (The x2 company) by 3Com (A K56flex Alliance member).

What should you expect from 56K Analog modems?

Time for the truth about 56K Analog modems. Before you spend a lot of money buying one, there are a few things you should be aware of:

• There is no guarantee that you will get a 56K connection.
• Many telephone lines are too noisy; they will only generate 28.8 to 44 Kbps connections.
• Many phone lines (Est. 70% or more) do not meet the technical specifications required to make 56K Analog connections work.
• It is estimated that only about 5% of all U.S. phone lines will achieve speeds greater than 40 Kilobits Per Second.
• The Upstream channel (Data going from You to Us) is at most 33.6K at this time.
• Many users currently unable to make a 28.8 Kbps connection will probably see improved results using K56flex.

In short, you will likely see some improved performance compared to your current 28.8 modem, but there is no guarantee. The chance of actually connecting at 56 Kbps is very limited. If for some reason you need a connection that will offer this kind of speed, ISDN would be a better option. Contact U.S. Internet Sales for more information on our ISDN offerings, available in all Digital POPs.

U.S. Internet has not recommended any particular brand or type of modem. Some manufacturers that produce K56flex modems include Hayes, MultiTech, Boca and Motorola.

More Information

For more information on K56flex technology, visit Lucent Technologies' K56flex Homepage.