Page 182 - Computer_Science_F5

Key functions of the formatted and encoded, making it usable for the
application Layer receiving application.
(a) End-user services: The (d) Network transparency: The Application layer
application layer directly simplifies the complexities of the underlying Chapter Three: Advanced Computer Networks
offers network services network, providing an easy-to-use interface
FOR ONLINE READING ONLY
to both end-users and that lets applications communicate over the
applications. It plays a network. This abstraction eliminates the need
crucial role in facilitating for applications to handle the complex details
communication and the of network operations. Common Application
exchange of data between layer’s protocols and their functions are shown
software applications and in Figure 3.26
other resources within the APPLICATION LAYER
network. PROTOCOLS
(b) Protocol support: HTTP Application layer
The Application layer SMTP Presentation layer
FTP
supports a range of DNS Session layer
protocols that establish POP
rules and standards for the TELNET Transport layer
exchange of data between Network layer
network applications.
These protocols, such as Data link layer
HTTP, FTP, SMTP, DNS, Physical layer
and DHCP, are widely
used for various network Figure 3.26: Common Application layer protocols
communication purposes.
(c) Data encoding and The Application layer protocols are HTTP, SMTP,
FTP, DNS, POP, TELNET. Their functions are
presentation: While the explained below.
Presentation layer in
the OSI model usually (i) HTTP (Hypertext Transfer Protocol)
handles tasks like data This is a protocol that is used for transferring web
formatting, encoding, pages on the Internet. It enables browsers to retrieve
and translation, the and display web content from web servers.
application layer in the
TCP/IP model often takes (ii) FTP (File Transfer Protocol)
on these responsibilities. FTP allows transferring files between a client and a
Its role is to ensure that server on a network. It supports both uploading and
the data is properly downloading of files.

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Student’s Book Form Five

Computer Science Form 5.indd 173 23/07/2024 12:33