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Learn more about
DSL |
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Learn more about DSL
Experts and users alike agree that the information era cannot reach
its true potential without the widespread implementation of reliable
and high-speed data delivery systems. Until recently, only large firms
with huge corporate budgets could obtain high-speed connections to
the Internet. Several xDSL solutions have recently gained recognition
for relieving the bandwidth bottleneck by offering small and medium-sized
businesses an affordable way to obtain high-speed connectivity. xDSL
technology leverages the existing copper infrastructure, so that DSL
providers and their clients do not have to wait months for expensive
fiber or cable wiring to be installed for the first time. aDSL (Asymmetrical
Digital Subscriber Line) has received much attention for making high
speed Internet access affordable to residential consumers. However,
sDSL (Symmetrical Digital Subscriber Line) remains the solution of
choice for businesses, because they usually publish (upload) as much
as they consume (download).
I. Introduction to DSL
Q. What is DSL?
Q. Why has Intercom chosen xDSL as our product of choice?
Q. How does it work?
Q. Will DSL service include transmission of regular
voice telephone service?
Q. Will businesses want to replace their existing DS1
(T1) Internet service with DSL?
Q. What is the difference between DSL and ISDN?
Q. What is the difference between DSL and the cable
modem?
Q. What is xDSL or DSL?
II. Installation and Hardware
Q. What hardware does Intercom dsl require ?
Q. What is the DSL & T1 Installation Process?
Q. Can the phone company use my existing wire, or do
they have to install new copper wire?
Q. How close to the phone company must I be?
III. Uses for DSL
Q. What can I do with DSL?
Q. How many IP addresses can I get?
Q. Can my DSL line be affected by adverse conditions?
Q. Will my telephone work if DSL goes down?
Q. What can be used to safeguard DSL?
IV. DSL Maintenance
Q. Can my DSL line be affected by adverse conditions?
Q. Will my telephone work if DSL goes down?
Q. What can be used to safeguard DSL?
V. DSL Resources
I. Introduction to DSL
Q. What is DSL?
A. DSL, which stands for "Digital Subscriber Line"
is a technology for bringing high-bandwidth connectivity to homes
and small businesses over ordinary copper telephone lines. xDSL refers
to the family of Digital Subscriber Line technologies, such as aDSL,
sDSL, and iDSL. DSL gives you a connection that is incredibly fast.
Connection speeds for DSL typically range from 1.54mbps to 512Kbps
downstream, and around 128Kbps upstream. Typical home users use a
modem to connect through their phone line. to compare, your modem
runs at 56,000 bits per second. Even the slowest DSL connection runs
at 256,000 bits per second. That's 4 times faster! in addition, allows
for one line to carry both voice and data signals, and for the data
part of the line to be continuously connected.
DSL achieves higher data transfer rates by utilizing more of the available
bandwidth spectrum. Ordinary telephone service only makes use of the
0 - 3400hz frequency range, which accounts for the 56kbps speed limit
on standard analog modems. DSL eludes the 3400hz frequency boundary
by outmoding the digital-to-analog conversion that modems perform,
and connecting both ends digitally. Hence, larger bandwidth is available,
allowing for higher transfer rates. DSL's use of the existing twisted
pair infrastructure makes it cheaper to install than other services
which require additional cable to be laid. And unlike cable modems,
DSL is not a bus technology, so the bandwidth available to the end
user is more consistent.
However, despite all its positive attributes, DSL deployment is not
yet ubiquitous. For instance, in order to be eligible for DSL, the
end user must be geographically within a certain distance from the
central telephone office ("C0") otherwise the signal degradation
is too great and DSL is unfeasible (for aDSL, that distance is two
miles). DSL is relatively new, so it's not yet available in all areas,
thus you have to be near a Bell Atlantic Central Office (CO), and
Intercom must be able to support DSL in your area.
Intercom covers many areas right now, and as DSL popularity grows,
Intercom will expand to most areas. Please give us a call at (212)
480-4076 or fill out our pre-qualification form at the Order Now! page
to see if DSL is available in your area. it pays to investigate DSL's
availability in your area, as it is a faster alternative to Analog
Modems, ISDN, and Cable Modems. And it is a cheaper alternative to
T1 and Frame Relay Internet access.
Q. Why has Intercom chosen xDSL as our product
of choice?
A. We have chosen DSL as our premier service for a number of
reasons. First, DSL technology is faster than other remote access
technologies such as Analog Modems, ISDN, Cable Modems, or wireless
solutions. Second, DSL provides a very secure remote access solution
over a dedicated copper telephone line from the central office to
the clients' home or business. Third, DSL is cost-effective to implement,
requiring no expensive engineering or infrastructure build-outs. Fourth,
because DSL technology utilizes the existing copper wiring infrastructure,
DSL can be deployed much quicker than some of the other high-speed
solutions. Fifth, DSL has voice over data capability and VPN capability!
Q. How does it work?
A. DSL sends a special signal on your existing telephone line.
It requires a special circuit card at the telephone company's nearest
office, and it requires special equipment at your office or home,
known as a CPE (Customer Premise Equipment). A technician from Intercom
must visit your home to install the CPE. Unlike ISDN, DSL doesn't
change your phone line in any way. You can still use the same telephone
you use now.
Q. Will DSL service include transmission
of regular voice telephone service?
A. Yes, once the FCC (Federal Communications Commission) ruling
goes into effect, DSL service will share a customer's telephone line
(POTS) without affecting the customer's ability to place and receive
voice calls. this means that customers do not need to provision a
second phone line for DSL service. They can keep their existing phone
number and add DSL as a feature to that line. You can even use your
DSL connection while talking on the phone. The DSL signal itself,
is a very, very high pitched sound on your phone line. It is far too
high pitched for you to hear, so you won't even notice it while talking
on the phone. When you pick up your phone, you'll get a dial tone,
and if people want to call you, they will be able to.
Q. Will businesses want to replace their
existing DS1 (T1) Internet service with DSL?
A. Yes. We believe that eventually, DSL will replace T1 for
most business use. There are clear technological differences between
DSL and T1 Internet service. DSL is a relatively new technology, whereas
T1 is an older, established technology. While technology tests repeatedly
demonstrate that DSL is extremely reliable, businesses tend to rely
on more established technologies when business critical data is at
stake. Another difference is in regard to availability. currently,
T1 service is still more widely available than dsl service. the final
difference is that DSL service is significantly cheaper than T1 service.
This is because with DSL, there are no local loop charges paid to
bell atlantic.
Q. What is the difference between DSL and
ISDN?
A. ISDN, once thought to be a good solution for speedy Internet
access is now getting a bad rap, and for good reason. ISDN is a very
expensive, 128kbps dial-up connection. With ISDN, a customer pays
a per-minute usage to the Telco which usually ends up being a lot
more than he/she bargained for. In short, you pay a lot and get little
for it. DSL, on the other hand, is a connection that is always "on".
there is no dialing up with DSL. There are no usage based fees, making
DSL a much more cost-effective solution, and DSL is faster than isdn,
as speeds range from 144kbps - 1.5mbps.
Q. What is the difference between DSL and
the cable modem?
A. First, xDSL and cable modems both offer a dedicated service,
however xDSL provides it over a private telephone line, while cable
modems provide it over a shared media. This one factor makes a world
of difference. Even though cable modems have greater downstream bandwidth
capabilities (up to 30 Mbps), that bandwidth is shared among all the
users on the line and will vary as more users in a neighborhood go
online at the same time. Cable modem upstream traffic will also be
slower than xDSL either because of the slow speed of the cable modem
or because of the rate reductions produced by competition for upstream
bandwidth slots.
The biggest difference between xDSL and cable modems, however, is
the number of lines available to each. There are no more than 12 million
homes that can support two-way cable modem transmissions and this
number will not reach the number of telephone lines for many, many
years. Additionally, many of the older cable networks will need significant
upgrading before they can offer high-speed service because of the
incapability of offering a return channel.
Q. What is xDSL or DSL?
A. DSL stands for 'Digital Subscriber Line'. It is a dedicated,
digital circuit from your home to the telephone company's central
office, using normal, copper telephone lines. DSL also provides a
separate channel for voice phone conversations, which means analog
calls (voice, fax, etc.) can be carried at the same time high-speed
data is flowing across the line. xDSL is a generic term that includes
several variations:
The Major xDSL Technologies
aDSL (Asymetrical Digital Subscriber Line) - aDSL offers a wide variety
of downstream & upstream rates. aDSL has greater downstream or
down load speeds than upstream or upload speeds (hence the "Asymmetric"
name). aDSL is ideal for consumers, or those that just want to surf
the web.
sDSL (Symmetrical Digital Subscriber Line) - sDSL is intended to provide
the same bandwidth in both directions. Intercom offers a range of
bandwidth options from 160k to 1.57mbps to suit individual business
needs. however, the distance over which this can be achieved is less
than 8,000 feet.
Some Other xDSL Technologies of the Future:
raDSL (Rate Adaptive DSL) - similar to aDSL, however with rDSL, modems
are able to automatically change their transmission speeds.
vDSL (Very-High Rate DSL) - the newest of the DSL technologies.
iDSL (ISDN DSL) - iDSL provides up to 144kbps transfer rates in each
direction and converts ISDN into DSL. This option is not upgradeable nor
widely available.
Q. What does dsl cost?
A. The only costs are DSL setup, hardware and monthly service.
For sDSL monthly service, prices range from $119 to $499. For business aDSL,
monthly service prices start at $99. For more details on
pricing, please see our web site.
II. Installation and Hardware
Q. What hardware does Intercom dsl require
?
A. You will need a nic (network interface card) to install
in your computer or computer network. You will also need a modem or
a router, which you may choose to rent or buy from Intercom. There
are a few equipment options. You can purchase, or rent the netopia
R7100 or the Flowpoint 2200 or 2100 router. Or you can purchase, or
rent a modem. The Netopia M7100 modem or the 5250 modem. The modem
or router will connect to the DSL lines as well as well as a port
of connection to your NIC. On the phone company side, every CO will
have a device called a DSLAM. This will directly connect you to the
backbone network of your ISP.
Q. What is the DSL & T1 Installation Process?
A. Intercom checks to see whether DSL is available to you,
by doing an online "prequal". If DSL is available to you,
Intercom will send you a contract. Upon receiving the contract and
initial payment from you, Intercom will submit your order to Covad
or Northpoint for processing. A few weeks later, Intercom gives you
a "FOC date". Bell Atlantic will come down to your site
and install a new copper line. This line will be used exclusively
for data transmission. Once the new line is up, A Covad or Northpoint
engineer will deliver and configure the router, and complete the inside
wiring. This is referred to as the "IW" appointment. Once
this is done, your DSL will be up on the following business day.
Q. Can the phone company use my existing
wire, or do they have to install new copper wire?
A. They will need to install a new copper line. The cost of
this is included in your monthly service. You will not need to deal
with Bell Atlantic at all. All billing and scheduling goes through
Intercom.
Q. How close to the phone company must I
be?
A. You must be less than 18,000 feet away from the nearest
Bell Atlantic Central Office. Beyond that, the data rates of dsl begin
to degrade. If you are 16,000 or more feet away from the CO, only
the slower speeds are available.
III. Uses for DSL
Q. What can I do with DSL?
A. DSL will let you use the Internet as it was meant to be
used. you can surf the web with speed and ease. web pages will snap
up on your screen. you can host a dedicated server, or a web site.
you will have an "always on" connection to the internet.
Q. How many IP addresses can I get?
A. You will be able to get as many as you need. Depending on
the DSL speed you order, you will get anywhere from 1-13 IP addresses
included free with the service. We also utilize a routing protocol
known as "IP with NAT". This enables you to have 254 internal
IP addresses and 1 external IP. IV. DSL Maintenance
Q. Can my DSL line be affected by adverse
conditions?
A. In the rare instance that lightning strikes your phone line,
there may be dangerous spikes in your phone line. or if weather is
so inclement that your phone line goes down, your DSL will go down
as well.
Q. Will my telephone work if DSL goes down?
A. Most likely, yes. your telephone will probably be alright.
But conversely, if your telephone doesn't work, then its a safe bet
that your DSL service won't be available either.
Q. What can be used to safeguard DSL?
A. A surge protector that hooks up to your phone line will
help to safeguard your dsl connection from power surges, like the
one used for analog modems should work fine. Also, the line to your
computer should have protection to eliminate the possibility of frying
your computer and other peripherals.
IV. DSL Maintenance
Q. Can my DSL line be affected by adverse
conditions?
A. In the rare instance that lightning strikes your phone line,
there may be dangerous spikes in your phone line. or if weather is
so inclement that your phone line goes down, your DSL will go down
as well.
Q. Will my telephone work if DSL goes down?
A. Most likely, yes. your telephone will probably be alright.
But conversely, if your telephone doesn't work, then its a safe bet
that your DSL service won't be available either.
Q. What can be used to safeguard DSL?
A. A surge protector that hooks up to your phone line will
help to safeguard your dsl connection from power surges, like the
one used for analog modems should work fine. Also, the line to your
computer should have protection to eliminate the possibility of frying
your computer and other peripherals.
V. DSL Resources
www.dslreports.com
www.xdsl.com
DSL Standards
American National Standards
Institute
Standards Committee -
T1 Telecommunications |



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