Analog vs ISDN vs DSL: Which Connection Is Right for You?
by Brian McConnell
Until recently, businesses had two choices when connecting to the
internet. They could pay about $20 per month for a slow, often busy,
dialup (modem) connection to the internet. Or, they could pay about
$2,000 per month for a fast, dedicated connection called a T1 line.
In the past two years, several new alternatives have become
available, and will become commonplace over the next few years. This
article will help you pick the right internet connection and save money when you shop for services for your business.
Currently available internet connections fall into the following
general categories: POTS (plain old telephone service), ISDN (integrated services digital network),
T1/Frame Relay, DSL (digital subscriber line), cable modem, and wireless internet service. Each type of
connection has its stengths and weaknesses. Typically, only one or
two of these options will be available in a given neighborhood
(availability is one of the big issues; more on that later).
POTS—Plain Old Telephone Service
By far, the most common type of internet connection is the dialup
modem connection. New high speed modems deliver speeds of up to 56
Kbps (56,000 bits of information per second). While this might sound
fast, 56 Kbps is not fast enough for videoconferencing, multimedia
applications, large file transfers, etc. While this is fine for the
casual user, businesses will typically want higher speed
PRO: Cheap and universally available
CON: Slowest type of connection available
ISDN has been available in some parts of the country for nearly a
decade. Envisioned as the "POTS line for the next century," ISDN
is now used to deliver higher internet connection speeds than analog
modems. ISDN delivers connection speeds up to 128 Kbps, about 4 times
faster than a typical modem and is also used for
The main problem with ISDN: the telephone companies overprice it
(you have to pay per minute of use), and it's not dramatically faster
than analog modem connections. In many cases, you barely notice the
improvement over a good 56 K modem.
PRO: Faster than analog modems, widely available in most metro
CON: Telcos overcharge for use, not dramatically faster than analog
T1/Frame Relay Service
T1/Frame Relay are commonly used to connect offices to the
internet. Rather than ordering dialup service for each user, a
company will buy a high speed connection which is shared by the
entire office. T1/Frame Relay deliver speeds up to 1.5 Mbps
(1.5 million bits of information per second), about 30 times faster
than the best analog modem connection, and about 12 times faster than
an ISDN connection.
T1/Frame Relay are available from almost every telephone
exchange, so availability is not usually an issue. The problem is
cost. T1/Frame Relay service is not cheap. A typical T1
internet connection costs about $2,000 per month, or nearly $25,000
PRO: Much faster than dialup service, widely available
DSL—Digital Subscriber Line
DSL (digital subscriber line) is a revolutionary new service which
delivers high data speeds at much lower prices than T1 or Frame Relay
service. DSL lines operate at different speeds, depending on the
configuration, and on your distance from the telephone company
central office. Speeds typically range from around 384 Kbps to 1.5
Mbps (T1 speed). Some versions of DSL can deliver speeds up to around
6 Mbps (6 million bits per second). There are many different flavors
of DSL service. The most popular types are SDSL (symmetric DSL) and
ADSL (asymmetric DSL).
SDSL typically delivers up to T1 (1.5 Mbps) speeds in both
directions (from the internet to you, and from you to the internet).
SDSL is essentially a cheaper replacement for a T1 line. This is a
popular class of service for businesses that are hosting web sites
and other applications on their networks. Service typically prices
out cheaper than T1 service, often under $1,000 per month. Most
vendors offer slower speed service with prices starting around $200
per month. Maximum speeds available to you will depend on your
distance from the telephone company's central office.
ADSL delivers more information downstream (from the internet to
you) than upstream (from you to the internet). Most small businesses
and individual users spend most of their time retrieving information
from the internet (i.e., browsing web pages, downloading files,
playing a sound clip, etc.). This asymmetric approach allows the same
circuit to carry data more efficiently. Since a large block of
upstream bandwidth would be wasted, it is used instead to send data
downstream. ADSL delivers downstream speeds ranging from 128 Kbps to
several megabits (as high as 6 Mbps), and delivers upstream speeds
ranging from 64 Kbps to 1.5 Mbps. This varies by configuration, and your distance from the telephone company's central
office. Pricing ranges from as low as $50 per month for relatively
slow speeds, to several hundred dollars per month for 1.5 Mbps or
faster service. It is dramatically less expensive than T1 or Frame
Relay service, and usually just as fast.
The main issues with DSL are availability and
compatibility. DSL is being widely deployed only
within major metropolitan areas. Rural areas are unlikely to
have DSL in the near future. Furthermore, since DSL has proven to
be popular, there can sometimes be considerable delay
having DSL installed. The other big problem is
compatibility. There are many flavors of DSL. There is work
underway to create a universal standard for DSL. However, it
will be a while before the standard is widely supported.
Read "DSL and ADSL"
PRO: High speed service, very affordable, adapts to line
CON: Not widely available, incompatibility between vendors
Cable modems offer a very inexpensive way to connect your office
or home business to the internet. Cable modems operate somewhat
differently than conventional modems. Whereas a conventional modem is
wired to a dedicated circuit which runs from your location to the
phone company, a cable modem uses the cable TV company's system as a
shared data network (sort of like an intercom system). All of the
devices connected to the network can talk and listen to each other.
Cable TV systems are designed to deliver a lot of information
(moving pictures and audio) from the head end (central distribution
point) to users (television sets). These networks are capable of
carrying large amounts of computer data in the downstream direction.
They do not usually carry as much information in the upstream
One problem with cable modems is variability of speed. If many
users are using the network simultaneously, your connection speed
will decrease. It is basically impossible to precisely predict
connection speeds. On average, cable modems deliver between 300 Kbps
to 1.5 Mbps. Many vendors are instituting usage policies and are
managing the bandwidth to better provide a specific speed level to
PRO: Very inexpensive (slightly more than dialup service),
CON: Variable quality of service, not widely available to businesses
Wireless Internet Service
If you live in a rural area, or in a downtown metropolitan area,
wireless internet service can deliver very high connection speeds
without using conventional phone lines. This is a particularly useful
way to "wire" an office building in a downtown location. Speeds vary
widely, from 1.5 Mbps to very high speeds (i.e., 45 Mbps). The
connection speed varies depending on the carrier, technology used,
and your distance from a receiving station.
This technology is still underutilized and hard to find. There are
now major players in this market that promise to increase
availability over the next few years. While not necessarily a first
choice at this time, in the future, wireless high speed service will
rival all the other forms of wired high speed service.
PRO: Very high speeds, independent of land-based telephone
networks, cost effective
CON: Only available in very specific regions
What Connection Is Best for Me?
The answer really depends on what is available in your area, and
what you are trying to do. This article assumes that you are a small
to mid-sized business that plans light to moderate internet use
(i.e., you are not hosting a high traffic web site). If DSL service
is available in your area, this is probably your best choice in terms
of performance and cost. The next best thing is cable modem service,
with the caveats about unpredictable, variable performance. If
neither cable nor DSL service is available, and you require a high
speed (>128 K) connection, then you're probably stuck with
T1/Frame Relay service, although wireless may also be an option. If
you don't require high speed connectivity, then a shared ISDN
connection will provide decent performance at a reasonable price.
Hello Direct has partnered with
to offer DSL and other data services to customers.
has a web search engine that enables you to search for pricing and
availability for high capacity voice and data service in your
If you have any more questions regarding high speed internet
access or any other telecommunications technology-related question,
hop on over to my "Ask
Brian" page and post a question there.