WHAT IS
DSL?
Symmetrical Digital Subscriber Line (DSL) is a new modem based technology that
allows high-speed transmission of data over an existing telephone line. NYI's
line of DSL products is named DSL Solutions. Customers located within 16-18
Kft. of an DSL equipped central office will be able to upload and download
multimedia and high-speed data communications over a single telephone line.
Connections to Internet providers or corporate LANs are virtually continuous.
Delays associated with call setup or busy signals will be a thing of the past.
One click of an icon and connection is immediate. A company employee working at
home will be able to access his or her company's data network just as
effectively as if from the office. DSL technology provides a clear economical
growth path for such future high-speed services such as video on demand, home
shopping, distance learning and others that will be deployed.
DSL TERMINOLOGY
- ADSL - Asymmetric Digital Subscriber Line Modems attached to twisted pair
copper wiring that transmit from 1.5 Mbps to 9 Mbps downstream (to the
subscriber) and from 16 kbps to 800 kbps upstream, depending on line distance.
- HDSL - High bit-rate Digital Subscriber Line - Modems on either end of one or
more twisted wire pair that deliver T1 speeds. At present, this requires two
lines.
- ISDN - Integrated Services Digital Network - Gives a user up to 56 kbps of
data bandwidth on a phone line that is also used for voice, or up to 128 kbps
if the line is only used for data.
- LOCAL LOOP - A pair of wires, moderately twisted for the entire length
between the telephone company's end office and the user premises (the common
telephone set) form a loop, so it is referred to as the local loop. This loop
provides a user with access to the global telecommunications infrastructure
that is installed all over the world. The local loop has been historically
designed to provide voice grade audio service. The circuit is powered from the
central office with 48V (open circuit voltage) limited in current to a value
somewhat higher than 20mA. This current is used for signaling phone access,
burning off moisture, breaking through metalic oxides caused by corrosion, and
powering a carbon microphone. The original telephone equipment contained no
active electronics. The actual wiring of the local loop may be considered to be
a lossy transmission line. DSL uses whatever frequencies will propagate on this
line for purposes of digital data transmission. T1 modulation (alternate mark
inversion) has been doing this for years. DSL extends the capability by using
modern technology to increase the data rates and distances spanned.
- POP - Point of Presence - A node of an ISP containing a DSU-CSU, terminal
server and router and sometimes one or more hosts, but no network information
center or network operations center.
- POTS - Plain Old Telephone Service - Basic voice service available in
residences throughout the United States.
- RADSL - Rate Adaptive Digital Subscriber Line - A version of ADSL where
modems test the line at start up and adapt their operating speed to the fastest
the line can handle.
- SDSL - Symmetrical Digital Subscriber Line - HDSL plus POTS over a single
telephone line. This name has not been adopted by a standards group but is
being discussed by ETSI. It is important to distinguish, however, as SDSL
operates over POTS and would be suitable for symmetric services to premises of
individual customers.
- TELCO - Telephone Company - Generic name for telephone companies throughout
the world which encompasses RBOCs, LECs and PTTs.
- VDSL - Very high bit-rate Digital Subscriber Line - Modem for twisted pair
access operating at data rates from 12.9 to 52.8 Mbps with corresponding
maximum reach ranging from 4500 to 1000 feet of 24-gauge twisted pair.
|
|
|
NYI
OFFERS
NYI specializes in DSL for businesses, which require sDSL. sDSL has many
features that make it comparable to T1 lines, with one very distinct
characteristic. The price points of sDSL are approximately 50% or less than the
cost of a comparable T1 line, giving sDSL an excellent price/performance ratio.
Some features of the sDSL products are:
- Router Included
- Static IPs Included
- Technical Support Included
- Firewall Services Available |
|