1-Meg Modem
Encyclopedia
The 1-Meg Modem in telecommunications was a DSL modem created by Nortel
Nortel
Nortel Networks Corporation, formerly known as Northern Telecom Limited and sometimes known simply as Nortel, was a multinational telecommunications equipment manufacturer headquartered in Mississauga, Ontario, Canada...

 which conforms to the ADSL Lite standard. The 1-Meg Modem was the first xDSL modem to gain approval and registration under FCC Part 68 Rules.

Technical details

The 1-Meg Modem can be deployed up to 18000 feet (5,486.4 m) from the central office providing a downstream bit rate
Bit rate
In telecommunications and computing, bit rate is the number of bits that are conveyed or processed per unit of time....

 of 960 kilobits per second (kbit/s) and a maximum upstream
Upstream (networking)
In computer networking, upstream refers to the direction in which data can be transferred from the client to the server . This differs greatly from downstream not only in theory and usage, but also in that upstream speeds are usually at a premium...

 rate of 120 kbit/s over 24 gauge wire. The second generation could achieve a transfer rate of 1280 kbit/s downstream and 320 kbit/s upstream. Unlike most ADSL modems which use Asynchronous Transfer Mode
Asynchronous Transfer Mode
Asynchronous Transfer Mode is a standard switching technique designed to unify telecommunication and computer networks. It uses asynchronous time-division multiplexing, and it encodes data into small, fixed-sized cells. This differs from approaches such as the Internet Protocol or Ethernet that...

 (ATM) virtual circuits to carry data, the 1-Meg Modem used Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

 which makes the product easy for most residential users to install themselves but ill suited for applications that require quality of service
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...

 to be enforced. At the telephone company switch the installation was relatively simple when the switch was a Nortel DMS Switch
Digital Multiplex System
Digital Multiplex System is the name shared among several different telephony product lines from Nortel Networks for wireline and wireless operators...

. The customer's line card
Line card
A line card or Digital Line Card is a modular electronic circuit on a printed circuit board, the electronic circuits on the card interfacing the telecommunication lines coming from the subscribers to the rest of the telecommunications access network.A line card commonly interfaces the twisted pair...

 must be swapped with a line card that supported the 1-Meg Modem and also a card must be added to the drawer that would manage all data from the 1-Meg Modem cards in the drawer.

History

At the time the modem was released telephone companies were fearing competition from cable modem
Cable modem
A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a HFC and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high...

s. However, early DSL technology was too costly for wide deployment.
By October 1998 Nortel claimed more than $1 billion in sales which, in their words, had "the potential for more than one million end-user lines." The modems were originally tested at Northern Illinois University
Northern Illinois University
Northern Illinois University is a state university and research institution located in DeKalb, Illinois, with satellite centers in Hoffman Estates, Naperville, Rockford, and Oregon. It was originally founded as Northern Illinois State Normal School on May 22, 1895 by Illinois Governor John P...

dormitories and worked well even though the school's wiring was relatively old.

External links

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