56K
The term 56K refers to a new generation of modems that improve the speed of communication between personal computers and the Internet. The previous speed standard of v.34 provided communication at speeds as high as 33,600 bits per second (bps). The new 56K modems increase that speed to a theoretical maximum of 57,600 or 56 Kbps. In the past, two different technologies emerged enabling 56K communication: K56flex and x2. They have been replaced by a new, international standard for 56K data communications known as v.90.

ADSL
Asymmetric Digital Subscriber Line (ADSL) is the most popular form of DSL technology.

ADSL Lite
A lower data rate version of Asymmetric Digital Subscriber Line (ADSL).

Broadband
A term for high-speed, high-capacity Internet and data connections. CAPCarrier-less Amplitude/Phase (CAP) modulation; incoming data modulates a single carrier that is then transmitted down a telephone line. The carrier itself is suppressed before transmission (it contains no information, and can be reconstructed at the receiver), hence the adjective "carrier-less." CAP and DMT are two modulation systems currently on the market for ADSL.

CDSL
Consumer Digital Subscriber Line (CDSL) is a proprietary technology trademarked by Rockwell International.

DMT
Discrete Multi-Tone (DMT) multi-carrier modulation uses 256 QAM modulation tones simultaneously to create the ADSL signal. DMT is the basis of ANSI Standard T1.413, and has the support of other world standards bodies. CAP and DMT are two modulation systems currently on the market for ADSL.

DSL
Digital Subscriber Line (DSL) provides a dedicated digital circuit between a residence and a telephone company's central office, allowing high-speed data transport over existing twisted copper telephone lines. We currently offer two ADSL (Asymmetric Digital Subscriber Line) product options to support information transfer rates of 1.5+Mbps downstream and 384Kbps upstream, or 384+Kbps downstream and 128Kbps upstream.

EtherLoop
EtherLoop is currently a proprietary technology from Nortel, short for Ethernet Local Loop.

HDSL
High Bit-rate Digital Subscriber Line (HDSL) is generally used as a substitute for T1/E1.

IDSL
ISDN based DSL developed originally by Ascend Communications.

LAN
Local Area Networks.

MSO
Multiple service operator synonymous with cable provider.

NAP
Network Access Point (NAP) is a high-speed interconnection service that gives Internet Service Providers access to the new Internet infrastructure.

POTS splitter
A Plain Old Telephone Service (POTS) splitter, also known as a low-pass/high-pass filter, separates the voice and data portions of the DSL line. Current DSL technology requires two POTS splitters: one in our central office, and one in the customer's premises.

PVC
Private Virtual Circuit (PVC) is a point-to-point circuit from the customer premise equipment to either their Internet Service Provider (ISP) or Enterprise Network.

RADSL
Rate Adaptive Digital Subscriber Line (RADSL) is any rate adaptive DSL modem, but may specifically refer to a proprietary modulation standard designed by Globespan Semiconductor.

SDSL
Symmetric Digital Subscriber Line (SDSL) is a 2-wire implementation of (HDSL).

v.90
A new, international standard for 56K data communications.

VDSL
Very High Bit-rate Digital Subscriber Line (VDSL) is proposed for shorter local loops, perhaps up to 3000 ft.

WAN
Wide area networks.

XDSL
Refers to the family of digital subscriber line technologies, such as ADSL, HDSL, and RADSL.