56K Information

56k Backgrounder 56k Pitfalls 56k Troubleshooting Tips

NTS currently uses v.90/k56flex protocols for the Amarillo, Lubbock, Pampa, San Antonio, and Wichita Falls dialup phone numbers.

56k Backgrounder

56k technology requires 3 essential things to operate:

an Internet Service Provider that supports 56k access
a modem that uses the same protocols as your Internet Service Provider
a phone line that supports 56k access

Even if you have all three of these items, getting connected at a full 56k is impossible: the FCC has imposed a limit of 53,333bps for transfers of this nature. Generally speaking, 53k connections occur only under laboratory situations, and rarely, if ever, in the real world. Usually, if you have a compatible ISP, a compatible modem, and a clean phone line, you can expect connections in the 40-48kbps range. Also, please remember that 56k transfers take place only on downstream transfers (i.e. when you receive data on your computer). All transmissions from your computer to the ISP take place at a maximum of 33.6kbps.

If you are interested in the specifics of how 56k technology works, Rockwell has an excellent whitepaper describing how 56k modems achieve faster data communications.

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Important things to keep in mind when attempting 56k communications:

The speed at which your modem initially connects does not accurately predict how your modem/ISP will perform under real world circumstances. The initial connection speed reported by your communications software will be accurate only if you installed the correct driver for your hardware (usually supplied by the manufacturer). Even then, almost all modems manufactured within the past few years have a feature called fast retrain: the ability to speed up or slow down at any point during the communication to adapt to changing line conditions. Some modems connect aggressively at high speeds that they are able to maintain for only a short period of time. Other modems are more conservative at connect time and gradually speed up as line conditions allow. The best way to check your "real world" modem speed is to download a file across the Internet. Most web browsers like MS Internet Explorer and Netscape Navigator report the average transfer rate in a "File Download" window. Typical download speeds for 28.8k modems are in the 2.6-3.0KBps range. Typical 56k connections support downloads in the 4.5-5.0KBps range.

Even clean sounding phone lines may not support 56k transfers

56k technology demands that your computer/modem/phone connection be no more than 1 mile from your telephone company's Central Office. Unfortunately, this means that many, if not most, customers in rural areas can connect at a maximum of 33.6kbps.

Even if your office is downtown in a large metropolitan center, you may not get 56k connection speeds.

If your office uses a PBX phone system (if you do, you usually have to dial "9" or some other number to get an outside line) you will almost certainly not get 56k speeds. Usually, customers who use modems connected to PBX lines are lucky to get lower 20kbps, with some connecting at 19.2kbps or lower. You can solve this problem by contacting your local telephone company, or phone system administrator and having a direct modem line installed for data use.

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