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Dan Kegel's ADSL Page

The word NEW on a link indicates updated on or after 1 Aug 96.

U.S. West to deploy ADSL this year?

According to a press release from US West, both ADSL and single-pair HDSL lines were used in a technical trial earlier this year; a market trial will follow in late '96, and deployment in selected areas in '97.

GTE ADSL Field Trial in Texas

GTE is conducting a six month trial in the Dallas area. Participation will be limited to two libraries, a bookstore, and GTE employees. The modems, provided by Westell Technologies and Aware, Inc., will deliver 4 Mbps downlink and 500Kbps uplink. Routers and switches provided by Bay Networks will interconnect the customers and the Internet. See GTE's ADSL Home Page or their ADSL Trial Info page for details.

DSL Modem Cost Down To $2500

PairGain claims they'll be conducting field trials of consumer DSL gear this year! And they already have a distributor for their Campus products. Pairgain's blurb says a home version will be available for $995 real soon now, but the Campus version is out now; the distributor is quoting a minimum of USD $2500 for a standalone unit.

They claim maximum range of 8 miles, but that's only at the lowest speed, 384 kbits/sec, with the best wire, 19 AWG. At higher speeds or with thinner wire, the max range can drop below 2 miles.

You can use these to surf the net in style right now- if:

  1. you can order a 'dry pair' from your ISP to you through your Telco,
  2. your ISP offers a high-speed connect option,
  3. you have $600 - $1200/month to spend on your ISP's high-speed connect option,
  4. the total wire length from your ISP through the Telco CO to you is about 2 miles (5 miles for 384 kbits/sec), and
  5. you have at least $6000 to spend on equipment ($2500 for each DSL modem, and at least $1000 for routers or high-speed serial ports).

About ADSL

ADSL started out as the phone company's way to compete with cable TV by delivering both TV and phone service on your plain old copper phone line. Now it's also a good candidate for high speed Internet access.

The "A" stands for "Asymmetric", meaning the phone company can send lots of data to you, but you can't send much to them. Originally, only a tiny uplink of 16 or 64kbps was supported; recent flavors of ADSL support up to ten times that much.

ADSL is one member of a continuum of last-mile transport systems called DSL, or Digital Subscriber Line, which can carry about 1 to 6 megabits/sec over copper lines. It does not include any way to make long distance data calls, or even local calls. That's another matter entirely-- one which is still up in the air. ADSL was originally designed so you still can use it as a regular phone line when the power goes out, which would be a big improvement over BRI ISDN.

For the moment, the only form of DSL really being deployed is HDSL, which is more or less a direct replacement for traditional T1 service. T1 lines have been around forever, but require technicians to tune the line to perfection; HDSL modems can handle dreadful lines cheerfully, so should be much cheaper to install and run.

Other kinds of DSL are coming soon. In general, the fastest DSL schemes only go a couple miles; the slowest can go farther. It's a tradeoff.

For alternatives to ADSL, e.g. cable modems, see one of the many excellent sites now springing up:

Cisco's Introduction to Multicast IP Routing explains some of the technology needed to make serious video distribution over the Internet possible, something that ADSL will need if it is to avoid completely obliterating the backbone...

For more info, try these online sources:

ADSL Service Providers

Magazine Articles About ADSL

ADSL Magazines & Periodicals

ADSL Hardware Vendors

DSL Mailing List

Thanks to Mubashir Cheema (cheema@sparco.com) for setting this up! This is a good list. You can even read past messages via the Web.

To subscribe simply send email to majordomo@jupiter.sparco.com with 

 subscribe dsl
in the body of the message.

Other ADSL Web Pages

Thanks to Brad Knowles for help finding links, and to Rupert Baines for suggestions and corrections!
HTML 2.0 Checked!
Author: Dan Kegel <dank@alumni.caltech.edu>

Copyright 1995 Dan Kegel. All rights reserved.