Which
Internet access line is best for me? (dial-up, ISDN, ADSL, ADSL2+, SDSL)
Which of
the following access lines is best for me?
4 Dial-up (using
analogue modem and normal telephone line)
4 ADSL
4 SDSL
Dial Up (telephone line
and modem): If you are not already an Internet user and
are unsure of the benefits that access to the Internet will bring, or
alternatively if you only have infrequent or minimal requirement for Internet
access or your requirement is for nomadic access from different geographical
locations, then probably the cheapest method of access is a ‘pay-as-you-use’
dial-up Internet access service. A number of providers offer such services:
there is no subscription charge, but instead simply an online registration.
Service is charged directly by means of the telephone bill at a rate per minute
– for the duration of each call.
4 Call charges
for accessing such services typically lie around 0.5 – 2.0 Eurocent/minute (£
0.003-0.01).
4 Maximum speed
of dial-up connections is limited by the modem installed in your PC and is 56
kbit/s, although the actual data throughput is typically much lower than this:
it is limited by the total capacity made available by the provider in
connecting the ‘dial-in-point’ to the Internet itself. This capacity must be
shared between many users. Typically only 1/50 of the registered users may use
the capacity at any one time. In addition, the data throughput rate of dial-up
lines using modems is also restricted by a high incidence of data errors (poor
quality lines and noise on the line require that errored data be
re-transmitted)
4 Limitations: it is sometimes necessary to make
several calls to the dial-up number before a connection can be established.
Particularly in the evening it may be necessary to wait until a quieter time
before a connection can be established. And once a connection is established,
website page download times may be quite lengthy. Many modern websites are no
longer designed with dial-up users in mind.
Dial Up (ISDN): If your usage of the Internet is only occasional, but
you find the speed of analogue dial-up access with a modem a little too slow,
then the right solution for you may be an ISDN dial-up connection. For this you
will need an ISDN network card installed in your PC. Access and charges are
very similar to dial-up modem access (indeed in most cases you will call the
same dial-up access point).
4 Call charges
for accessing such services typically lie around 0.5 – 2.0 Eurocent/minute (£
0.003-0.01).
4 Maximum speed of ISDN (digital) dial-up
connections is 128 kbit/s when the modem and provider support channel bundling
(2 x 64 kbit/s channels operating together as a single connection). Otherwise
the maximum bitrate is 64 kbit/s. The 64 kbit/s rate may appear only slightly
faster than the 56 kbit/s of analogue dial-up modems, but in reality the
performance is much better, since ISDN lines are not prone to high rates of
data errors as is the case with analogue modems. But as with dial-up using an
analogue modem, the actual data rate is limited by the total capacity made
available by the provider in connecting the ‘dial-in-point’ to the Internet
itself. This capacity must be shared
between many users. Typically only 1/50 of the registered users may use the
capacity at any one time.
4 Limitations: it is sometimes necessary to make
several calls to the dial-up number before a connection can be established.
Particularly in the evening it may be necessary to wait until a quieter time
before a connection can be established. And once a connection is established,
website page download times may be quite lengthy. Many modern websites are no
longer designed with dial-up users in mind.
ADSL/broadband:
If you are a frequent user of the Internet, ‘surf’ for long periods of time or
have a need for large scale data transfer, an ‘always on’ connection or high
bandwidth applications (such as gaming, software downloading, music or
video-on-demand, Internet telephony (VOIP) etc.) then the right solution for
you is ADSL or an equivalent broadband service. For this you will need an
ethernet network card (10/100baseT) installed in your PC.
4 Charges are typically around €15-25 monthly for line
connection and €5-€10 in data transfer charges (dependent on volume, or based
on a flatrate charge) [total charges €20 (£15) to €35 (£28) per month]. For serious Internet users, the
predictable and limited charges offered by a DSL volume flatrate charge may be
the prime motivation for changing to ADSL.
4 Maximum speed
of standard ADSL connections is 8 Mbit/s in the downstream direction (from
Internet to ADSL user) and up to 1 Mbit/s upstream (from ADSL user to network)
4 Limitations: The prime limitation is that ADSL
is not available to everyone – not all exchange areas are equipped for ADSL. In
addition, for very heavy users or for bandwidth-hungry applications (such as
live video or TV-streaming, large scale software downloading, video-on-demand,
high speed 3D gaming etc.) the downstream bitrate may be a limitation. The
upstream limitation of 1 Mbit/s may also be a limitation for users requiring to
send a lot of data (‘peering’ applications, large file transfer, back-up
applications, web server connection at the site etc.). In this case, ADSL2,
ADSL2+ or SDSL may be better suited.
ADSL2/ADSL2+/broadband:
If you are a frequent user of the Internet, ‘surf’ for long periods of time or
have a need for largescale data transfer or high bandwidth applications (such
as gaming, software downloading, music or video-on-demand, and the 8 Mbit/s
downstream bitrate of standard ADSL is a limitation, then ADSL2 or ADSL2+ is
the right solution for you. Alternatively, given that ADSL2+ is fast becoming
the ‘standard’ type of ADSL offered by ADSL service providers, you may elect
for ADSL2+ directly anyway. By equipping yourself from the start with an ADSL
2+ compatible DSL modem, you avoid the possible need for a new modem later. To
use ADSL2 or ADSL2+ you will need an ethernet network card (10/100baseT)
installed in your PC.
4 Charges are typically around €30 monthly for line connection
and €5-€10 in data transfer charges (dependent on volume, or based on a
flatrate charge) [total charges €40 per month]
4 Maximum speed
of ADSL2 connections is 12 Mbit/s in the downstream direction (from Internet to
ADSL user) and of ADSL2+ connections is 25 Mbit/s. Maximum upstream rate is 3.5
Mbit/s (from ADSL user to network)
4 Limitations: As with ADSL, not all telephone
exchange areas are equipped for ADSL2 and ADSL2+. In addition, the upstream
limitation of 3.5 Mbit/s may also be a limitation for users requiring to send a
lot of data (‘peering’ applications, large file transfer, back-up applications,
web server connection at the site etc.). In this case, SDSL may be better
suited.
SDSL:
For small businesses, an ADSL connection may be the perfect solution for
Internet access and inter-site datanetworking. However, for many businesses –
particularly those with large email or file servers, databases, website
servers, peer applications or data back-up arrangements, it is just as
important to have a high upstream
data rate (data transfer from customer site to network) as it is to have a high
downstream bitrate (data transferred
from the network or Internet to the local site). In this case, an SDSL
connection may be the best solution
4 Charges
are typically around €90 monthly for line connection and flatrate data transfer
charges
4 Maximum speed
of SDSL connections is typically 6 Mbit/s in both upstream and downstream
directions
4 Limitations: As with ADSL, not all telephone
exchange areas are equipped for SDSL. Where the data rate of 6 Mbit/s is not
sufficient then you may need to request a high speed leaseline (e.g. ethernet,
34 Mbit/s, 155 Mbit/s or Gigabit ethernet – 1000 Mbit/s) as your means of
connection to the Internet.