|
|
Advanced
How To Guide
Choosing an ISP and a Telecommunication Method
Leased Lines
Currently digital leased lines are the main option
for companies that have outgrown ISDN. A leased line
is a high bandwidth connection between two points -
usually between your company's premises and your ISP
but they can also be used between branch offices and
a head office. Companies including such as Eircom and
Esat can provide both leased lines and Internet access
while other ISPs will subcontract the provision of the
physical leased lines but provide the Internet access
themselves. The later option is not necessarily more
expensive as the ISP will purchase the leased line at
wholesale rates.
Leased lines are not readily available in all parts
of the country and waiting times tend to be shorter
in urban areas. The bandwidth of leased lines varies
from 64Kbits/sec up to 34Mbits/sec and your ISP should
be able to advise what bandwidth is most suitable for
your purposes. Leased lines can be upgraded after the
initial installation but it is better to over-specify
your bandwidth, as an upgrade may not be immediately
available.
As well as a higher speed connection, leased lines provide
a permanent, dedicated connection to your service provider
which means you can run sophisticated Internet applications
from your own office, such as hosting your own web site.
Most ISPs charge a fixed monthly fee with no download
limits, which makes budgeting for your Internet infrastructure
much simpler. Your connection will be covered by a service
level agreement (SLA). This should include a guaranteed
level of uptime - usually 99% or increasingly 100% -
which means you will be compensated if your leased line
goes down.
Frame Relay
Frame Relay is another high-speed transmission technology
that is generally used by companies with a number of
locations that they wish to connect for secure private
data communications. It operates at speeds from 64Kbits/sec
to 2Mbit/sec. Frame Relay generally operates over the
nation-wide ATM networks that a number of the larger
ISPs operate.
ATM
ATM allows for the transmission of voice, data and video
over a single connection at speeds of up to 622Mbits/sec
and is useful for companies with multiple sites. Access
speeds range from 34Mbit/sec to 622Mbits/sec. ATM is
generally the preserve of multinationals and other large
corporations.
Wireless
Wireless Internet access falls broadly into two camps
- fixed and mobile. Fixed wireless access is provided
by suppliers including Eircom, Chorus and Esat and gives
you a high-speed connection to your ISP without the
need for a leased line. A transmitter on the roof of
your premises connects to your ISPs nearest point of
presence; typically a receiver within line of sight
of your premises. Fixed wireless broadband is expected
to become popular in areas where DSL is not available
but it is not currently widely deployed in Ireland.
Mobile wireless access involves using a GSM mobile phone
to connect laptops and other mobile devices to connect
to the Internet . Your ISP does not have to specifically
support this feature, as it is the same as dial-up access
except using a mobile phone. The speeds attainable on
a GSM network are limited to 14.4Kbits/sec but Vodafone's
Work Anywhere service delivers speeds of 43.2Kbits/sec.
Issues to consider when choosing your Telecom options:
Cost
This includes a connection fee, ongoing payments to
the telecom operator and possibly the need to buy new
hardware or software when you change the type of telephone
connection.
Speed
The speed, or bandwidth, of your connection is a key
factor determining how long it takes to send a data
file down the telephone line. Below certain minimum
speeds, facilities such as video conferencing are impractical.
Your telephone connection is only one of the factors
determining your working speed. If your network or the
websites you most often deal with are completely overloaded,
things will be slow, no matter how fast your telephone
connection is. However, when considering different options,
you should ask about the average speed and/or the guaranteed
minimum speed of the line.
Note: GSM is a standard mobile phone. Analogue means
a standard old-fashioned home phone.
|
|
