This page has been written by and is copyright of Bill Gray, and is
published with his kind permission. Things move fast in telecommunications, and a little
of what he says is already out of date. It's still a useful contribution from an "early adopter".
So You Want ADSL in Spain?
Firstly, you need to check whether your telephone exchange/sub-exchange
(Centro/Centralita) is ADSL enabled.
To do this, go to the website of the Ministry of Science and Technology
at
click on the ADSL icon and in the resulting panel, click on "Busque la
demarcacion....."
This will bring up another panel into which you enter your telephone
number then click on Buscar.
If you see "disponible" in the result, you should be ok to go ahead,
otherwise you may see a date by which Telefonica plan to make the
service available at that exchange.
You can apply for the ADSL connection with any of the major ISPs,
including Telefonica itself (http://www.terra.es).
Several versions are offered, depending on what speed you want to
contract for - the higher the speed the more you'll have to pay.
The speeds are quoted as two numbers, (e.g. 256/128 , the lowest and
cheapest) and these are the maximum theoretical download/upload speeds
in kilobits per second (kbs).
In the more familiar notation, the example translates as 32/16
KiloBytes/second (KB/sec).
These maximum theoretical speeds are not attainable for various reasons,
and with the 256/128 connection the fastest sustained download I have
seen was 27KB/sec. This is of course a vast improvement on what I used
to see on DialUp, which was normally somewhere in the region of
2.5KB/sec.
Any download is affected by the speed of the site from which you are
downloading, naturally. If you're on a popular site you may be in a
queue with several hundred other people, all taking their turns to have
a packet sent to them. Also, if you are downloading on multiple PCs
simultaneously, the total download speed can't exceed the line's
maximum.
The actual telephone line does not need to be changed in any way, but
the terminator box just inside your house will be replaced by a similar
looking filter box which has two outputs - one for the phone/fax , the
other for the computer. The two are independent, and the phone can be
used whilst the computer is on line.
If the computer is not close to the filter box, a cable will be run
through to the " computer room ". This cable will terminate in a
standard telephone socket, but this cannot be used for a phone.
A cable runs from this socket to a special, expensive, ADSL modem
(Router). Some ISPs are offering free modem and cabling in their
efforts to secure customers; as always, shop around.
The Router can have a single output, or several. If the Router has a
single output and you want to connect more than one PC, a LAN hub
(Local Area Network hub) is necessary. In any case, each computer will
need to have a LAN card (Ethernet card) installed if it doesn't already
have one. Each LAN card is connected to the Router or to the hub by its
own cable.
At the other end of the telephone line, in the exchange, Telefonica
install a similar modem, permanently connected to the ISP. Thus, you
can't have ADSL with more than one ISP !! You can still receive
INCOMING E-mail from other ISPs but if you want to send any via another
ISP you'll need to retain your DialUp contract with them and keep your
installed dialup modem in place.
Once connected, your PC(s) will be online as long as they are powered
up, unless you unplug the cable which connects the PC's LAN card to the
Router. Multiple computers can be set up as equals (Peer to Peer
Network), or in a Server/Client relationship.
There are two schools of thought on the question of having computers
running permanently. My experience of mainframes and "mini" computers
has led me to the conclusion that it is better that they should run
permanently and only be switched off when necessary, as most hardware
problems seem to occur at power-up time. Each should have a UPS
(Uninterruptible Power Supply, known as SAI in Spain) to avoid problems
with power cuts and power surges. However, my (S.W.G.) own two PCs are
in a tiny room and generate a lot of heat, so I switch them off at
night, whereas Bill Hayles's machines run continuously.
Whether a PC is on permanently or not, under ADSL it will be on line
for much longer periods than before, and this makes it much more
vulnerable to attack by a hacker's scanning program, which scans all
possible Internet addresses looking for computers on line. This makes
a firewall essential!
Some Routers have built-in firewall (filtering) software, but this is a
mixed blessing. If your Router has such a firewall, it is important
that you be given the necessary information on how to disable/enable
the filtering, as the filtering can reject such things as voice
contacts, video conferencing and cookies, in which another computer
tries to establish a direct connection with your computer by sending an
unsolicited data packet, in the same way as a hacker does.
In any case, you will need a software firewall program running in each
PC.
Version History.
First Edition by Stan (Bill) Gray, January 2002
Edited Web edition May 2002.
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