How Does it Work?
A DSL modem or router is installed at your home or business . The DSL Router is equipped with a firewall or packet filtering and is configured to hide your local computers from the Internet for security.

In the telephone company central office the DSL line is connected to a DSLAM (Digital Subscriber Line Access Multiplexer). The DSLAM is connected through our routers directly to the Internet Backbone.

ADSL uses the same telephone that you use for regular telephone service. Your telephone operates exactly the same and you have a 24/7 connection to the Internet.

SDSL and IDSL utilize a separate telephone line that is dedicated for providing DSL service.

Security
Residential and single computer business installations utilize a modem that does not protect your computer from hackers. To protect your computer visit one of the many sites on the Internet regarding security. Both tips and software are available to protect your computer, now always connected to the Internet.

For business installations with more than one computer we provide a DSL Router that is equipped with a firewall and is configured to hide your local computers from the Internet for security.
DSL Flavors and Speeds
ADSL (Asymmetrical Digital Subscriber Line) is faster in the return (download) than send (upstream) direction. Upstream speeds are usually 128Kbps to 1.088Mbps while downstream speeds are up to 8.192Mbps. ADSL utilizes your existing telephone line. This reduces the time to install DSL from weeks to days.

HDSL (High bit rate Digital Subscriber Line) HDSL enables T1 (1.544Mbps) speeds over regular copper phone wire without the use of repeaters. HDSL requires the use of two telephone lines compared to a single telephone line (one pair) used by the other flavors of DSL.

RADSL (Rate Adaptive Asymmetrical Digital Subscriber Line) RADSL is a rate adaptive version of ADSL. Rate adaptive technology allows a service provider to adjust the bandwidth for a particular application or compensate for line length or quality. This adjustment can be pre-configured or self-adjusting.

SDSL (Symmetrical Digital Subscriber Line) SDSL is designed to provide high bandwidth in both directions. This is suitable for many business applications such as e-mail, file transfers and Web Site Hosting. Typical speeds are 144kbps to 1.544Mbps.

IDSL (Integrated Digital Subscriber Line) An ISDN based version of DSL that utilizes both B-channels and the D-channel for a fixed data rate of 144 Kbps in both directions. This is used for when the telephone line is too long to support ADSL or SDSL.

Typical download times for a large 1 Meg file are as follows:
standard modem - 4.6 minutes
144K - 56 seconds
192K - 42 seconds
384K - 21 seconds
768K - 10 seconds
1544K - 5 seconds

Distance
The speed that can be obtained using DSL is dependent on the distance (length of cable) between the user and the telephone company central office (C.O.) and the thickness of wire used by the telephone company. Typical maximum distances are as follows:

1.5Mbps - 10,500 feet (2 miles)
1.0Mbps - 12,300 feet (2.3 miles)
768Kbps - 13,500 feet (2.5 miles)
384Kbps - 22,500 feet (4.3 miles)
144Kbps - 35,000 feet (6.6 miles)*

*In many areas 144 Kbps (IDSL) is provided over digital carrier and fiber optic cable allowing unlimited distances to be obtained.
As new technologies and equipment are placed into service, speed and distance will continue to increase.

DSL vs. Cable
Cable modems are an alternative for broadband residential service but is not suitable for business-class broadband for the following reasons:

Service: Most business locations are not serviced by cable and therefore can not be connected. In addition, cable service has been historically unreliable. Each time the "cable goes out" so does your Internet connectivity.

Speed: The cable users are set up as a LAN or Local Area Network to share a single fiber connection among the hundreds (maybe even thousands) of subscribers. As more and more of your neighbors connect, your bandwidth or line speed diminishes proportionately. Cable companies typically can not guarantee a minimum available bandwidth. Once the initial speed has been determined and set at installation, your bandwidth never changes.

Security: Being on a Local Area Network does not provide for a secure connection for electronic commerce. Your connected neighbors and competitors will be able to intercept your credit card or other sensitive, confidential company data using a device called a sniffer. DSL is a direct connection between your business and our equipment located in secure telephone central offices. The DSL line is never shared!

DSL vs. T1 and Frame-Relay
T1 data lines are the most common high speed data lines in use today. They are used to carry both data and digital multiplexed voice channels (24 toll grade voice channels per T1). DSL is capable of providing T1 speeds within a limited distance to the telephone company central office (C.O.) at a fraction of the T1 price. The cost of a T1 is very high due to special requirements that are placed on the cabling between the C.O. and the user. These requirements include the removal of all bridging and taps and the installation of repeaters along the cable. At longer distances, DSL can provide Fractional T1 speeds. DSL is clearly a lower cost alternative to a T1 circuit.

DSL is not for mission critical corporate applications. A DSL outage does not receive a high priority from the telephone company to repair. T-1 and Frame-Relay circuits do receive high-priority and are specially marked at all connection points to notify the telephone company technician of a critical data circuit. Please contact us if you have a mission critical application. A combination of a high-speed DSL circuit with a lower speed DSL Express Frame-Relay circuit may be the most cost effective solution.

DSL Installation Questions and Answers
How long will it take to have my DSL installed?
Residential and single computer business Installations are performed by the user. We will ship you a complete kit to install the DSL modem. Installation is usually as simple as plugging the modem into your computer and into the wall jack. It usually takes 5-7 days to receive the DSL modem and installation kit.

Business installations in Dade, Broward and Palm Beach counties usually take 7-10 days. We can either ship you the DSL router if you have a computer person on-site or we will come out and install the DSL router for you.

Business installations outside of South Florida usually take 4-8 weeks. Equipment installed in the local telephone company office (C.O.) must be connected to your business by the local telephone company. Once the local telephone company installs and connects the DSL line, the line is tested to ensure the ordered speed is obtainable. Once the testing is completed we will immediately contact you and arrange for the installation of your DSL router.

Is there any reason my DSL line won't be installed?
Yes, technology on your phone lines such as repeaters, digital carrier systems, load coils and the lack of telephone company facilities (such as available lines) at your local telephone company office may prohibit or delay you in receiving DSL.

Will I definitely receive the speed that I ordered?
There is a chance that your line may only support a slower speed than you ordered due to several factors including the length and gauge of line servicing your home or business or the use of digital carrier between your business and the local telephone company office. If we can not provide the speed requested, we will contact you to determine if you want to proceed with the slower speed.

Do I need to add anything to my PC to receive DSL?
PCI, USB and Ethernet DSL modems are available. Businesses with more than one user are provided a DSL Router that connects to an existing Ethernet hub or switch. The hub or switch must have an available 10Base-T or 10/100Base-T port. Please contact DSL Express customer support for additional information.

Will DSL Express install perform the installation for me?
DSL Express will perform the installation for commercial users at no additional charge. DSL Express will perform residential installations at an additional cost of $99.00. Please contact DSL Express customer support for additional information.

DSL Glossary

10BASE-T The Institute of Electrical and Electronic Engineers (IEEE) specification for Ethernet over unshielded twisted pair cable at 10Mbps.
100BASE-T The Institute of Electrical and Electronic Engineers (IEEE) specification for Ethernet over unshielded twisted pair cable at 100Mbps.

ADSL Asymmetric Digital Subscriber Line. High speed technology utilizing existing phone lines to transmit data. Typical speeds are from 144Kbps to over 8Mbps currently. See DSL Types for more info.

ATM Asynchronous Transfer Mode. High Bandwidth packet technology that uses 53 byte fixed sized cells to deliver data, voice and video.

ATU ADSL Transceiver Unit. Equipment used for DSL technology. In the Central Office it is called ATU-C (central) and in the Customer locations it is called ATU-R (remote).

Backbone A central very high speed fiber network that is used to connect smaller, independent networks. Bandwidth A term used to describe the number of bits that can move across a communications system in a given amount of time.

BPS Bits per second. The number of bits passing a point every second. The rate of transmission for digital signals. Broadband Data transmissions of voice, data and video signals over a single medium at high speeds.

CLEC Competitive Local Exchange Carrier. The new competitors to the original Bells after deregulation. See also ILEC.

C.O. Central Office. The building used by telephone companies to connect local users to their infrastructure.

CPE Customer Premises Equipment. Terminating equipment supplied by carrier for use at customer site ie. Modems, phones, routers.

DS3 Digital transmission at 45Mbps, usually operates on fiber optics. Equivalent to 30 T1 circuits.

DSL Digital Subscriber Line. Technology that combines two way voice and data transmissions at very high speeds over normal phone lines. See DSL Flavors and Speeds for more info.

DSLAM Digital Subscriber Line Access Multiplexer. Equipment used in the telephone company Central Office to concentrate local DSL users onto a high capacity Backbone.

DSU Digital Service Unit. Digital device at customer premises to facilitate xDSL service. Also known as a Modem or Router.

Ethernet Term used to describe a baseband LAN specification originally designed by Xerox. IEEE 802.3 describes the current standards for this protocol.

Firewall A secure gateway or virtual wall between two different computer networks that will prevent unauthorized use or access.

Fractional T1 A portion of a T1 circuit that has been divided into 24 separate 64Kbps channels. Actual size is a multiple of 64.

Frame Relay A data communication technology based on packet switching of variable length frames that are protocol independent.

HDSL High bit rate Digital Subscriber Line. See DSL Flavors and Speeds for full definition.

IDSL Integrated Digital Subscriber Line. An ISDN based version of DSL operating at 144 Kbps. See DSL Flavors and Speeds for full definition.

ILEC Incumbent Local Exchange Carrier. All the original Bells are called ILEC's after the Telecommunications Act deregulation. All new competitors are known as CLEC's

ISDN Integrated Services Digital Network. Public circuit switched network that combines voice and data into a single medium. Usually runs at 64K or 128K, predecessor to DSL technology.

ISP Internet Service Provider. Company that provides connection to the Internet typically via a dial-up link

Kbps Kilo Bits Per Second. A measure of time relating to telecommunications speeds. One kilobit is 1,000 bits of information, the higher the number the faster the transmission speed.

LAN Local Area Network. A data communications networks of computers, printers, file servers, etc.. in a local environment.

Local Loop Also called the "last mile". The length of telephone wire from the local Central Office to it's final termination at customer premises. Usually about 1-3 miles or less.

Mbps Mega Bits Per Second. Like Kbps a measure of transmission rates. One Megabit equals 1,000,000 bits of information. 1.5Mbps is over 50 times faster than a 28.8 Kbps dial-up Modem.

NIC Network Interface Card. The hardware that handles the protocol conversion between your computer and a connected network. Used in DSL service to talk to router.

POTS Plain Old Telephone Service. As it sounds, your basic telephone service.

Repeater Electronic device used to regenerate and enhance signal quality over long cable distances.

Router Electronic device that transmits and receives data packets in a network.

SDSL Symmetrical Digital Subscriber Line. See DSL Flavors and Speeds for full definition.

T1 Digital transmission at 1.544Mbps. T1 is the most common transmission technique used in North America.

T3 Digital transmission at 45Mbps. Basically 30 T1 circuits.

TCP/IP Transmission Control Protocol/Internet Protocol. Open communication protocol that allows computers with different operating systems to communicate with each other on the Internet.

VPN Virtual Private Network. A network service that is provided over a public network that is secure and works like a private network.

WAN Wide Area Network. A network with devices over a wide geographical area.

xDSL Refers to all variations of the DSL family or technologies.