| The internet is
a conglomeration of interconnected networks - big
and small networks which are linked together to
form a single entity. It was setup in 1969 and its
growth has been explosive, catering for all parts
of life and culture. It is monitored by the Internet
Society. Each computer that connects to the internet
forms part of a network, which is why people can
access your computer and why WebShield's Online
Firewall is so beneficial. Your computer connects
to a POP or Point Of Presence, a local place of
connection via phone or dedicated line. The POPs
then connect to NAPs or Network Access Points,
which in turn connect to the internet via dedicated
backbones.
Information is sent from one computer to another
via routers, which are specialised computers that
administrate the sending and receiving of information.
Backbones are usually fiber optic trunk lines
(many fibre optic cables linked together for added
capacity). They range from an OC-3 (155 Mbps)
to OC-48 (2488 Mbps).
Each Computer that connects to the internet has
an IP Address or a unique identification number,
eg. 234.18.55.140 Computers handle these numeric
codes. Instead of an IP address, people use a
domain name to access computers or websites, eg.
www.bbcnews.com This text based system is known
as the DNS (Domain Name System). The internet's
DNS servers translate the text domain names into
computer readable IP addresses.
Internet servers handle all the transactions
of data. Dependent on the type of data and the
function required, a web, FTP or email server
may ensure its processing, eg. Your email software
will communicate with an email server, and your
web browser communicates with a web server.
The different functions available via a web or
email server are run through numbered ports, eg.
port 80 for a web server. |
