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Internet is a packet-switched network, in which information is broken into small packets and sent over
different routes at the same time, and then reassembled at the receiving end. TCP is the component
that collects and reassembles the packets of data, while IP ensures that the packets are sent to the right
destination.
Do you know?
TCP/IP was developed in the 1970s and adopted as the protocol standard for ARPANET (the predecessor
to the Internet) in 1983.
FTP
FTP stands for ‘File Transfer Protocol’. It is a set of rules for transferring files between two computers on
Internet. It is a commonly used protocol for exchanging files over any TCP/IP based network. The central
computer i.e., FTP server helps the users to upload and download files.
Using FTP, the client requests to initiate a file transfer, then the client and the server exchange files. FTP
allows communication between clients and servers but not between clients i.e., two people with FTP client
software cannot exchange files directly until the FTP server is in the middle.
The most common application of FTP is to download files from the Internet. An FTP address looks
like an address of a website, except that it uses the prefix ‘ftp://’ instead of ‘http://’. An example of
FTP site address is ‘ftp://planet.com/’. There are two types of FTP connections: ‘Anonymous’ and
‘Non-Anonymous’.
When connected to any FTP directory, the host system asks for the user’s name and password before allowing
access to the directory. With an anonymous FTP directory, the user’s name is always “Anonymous” and
the password is always the user’s e-mail address. While connecting to an FTP site that allows anonymous
logins, the user is not (frequently) prompted for a name and password. Hence, while downloading files
the users are most likely using an anonymous FTP login.
Non-anonymous FTP on the other hand, requires a unique username and password for the FTP directory
in question, which is provided by the FTP site administrator only. So the users are verified before they can
access or transfer files from their computer.
To make an FTP Connection
To make an FTP connection the user uses a standard web browser (Internet Explorer, Netscape, etc.) or a
dedicated FTP software program referred as FTP client. To connect to a FTP site using web browser, enter
the URL of the FTP site; ftp://ftpserver/pathname. For example, to connect to ‘ftp.sunet.se’, type the URL
ftp://sunet.se.
Downloading and Uploading
Downloading refers to transfer of file from a remote computer to the host computer. FTP helps to make
a directory on a computer connected to the Internet and to transfer a file from that directory on another
computer on the Internet.
The files can be downloaded from a FTP site even by an anonymous user. To download, the browser asks
for a name and location on the local computer to save that file.
Networking 21

