The application layer is the top layer of the OSI networking model. It provides protocols for user-oriented applications and common Internet services like file transfers, email, and directory browsing. Some key application layer protocols include HTTP, FTP, POP, SMTP, SSL, and Telnet. The application layer determines how data is transmitted between communication partners and ensures user authentication, privacy, and service quality.

1. APPLICATION LAYER
Group 7 > ITWD 111 A

2. CONTENTS
ITWD Report 7 > ApplicationLayer.pptx

3. SOFTWARE
Programs that tell the computer
how to perform tasks


SYSTEMS SOFTWARE
Consists of programs that interact
with the computer at a very basic
level
APPLICATIONS
SOFTWARE
Programs catering to the user’s
computing needs and relies on
systems for existence
OS | compilers | PC
utilities
E.
G.
MS Office suite | games
E.
G.
APPLICATIONS
SYSTEMS
HARD
WARE
FIGURE 1.1
Systems are housed through the
hardware. Applications run through the
systems software.

4. APPLICATION LAYER
End-user layer of the OSI networking
model
 COMMUNICATION PARTNERS
Identification
 SERVICE QUALITY
Identification

USER AUTHENTICATION
AND PRIVACY
Implementation
  
FIGURE 1.2
In application layer, there is providence of
services on the Internet, giving access to
file transfers, e-mailing, and directory
services.

5. APPLICATION LAYER
Protocols determining manner of data
transmission
 HTTP
Hypertext
Transfer
 FTP
File Transfer
 POP
Post-office
 SMTP
Simple Mail
Transfer
 SSL
Secure Socket
Layer
 Telnet
For remote PCs

6. LAYERS OF THE OSI
MODEL
Networking blueprint for efficient data
transmission
DATA UNIT Bit
EXAMPLE(S) DSL, USB
Transmission and
reception of raw bit
streams over a physical
medium
 
MEDIA HOST
 
DATA UNIT Bit/Frame
EXAMPLE(S) PPP, L2TP
Reliable transmission of
data frames between two
nodes connected by a
physical layer
DATA UNIT Packet
EXAMPLE(S) IPv4, IPv6
Structuring and managing
a multi-node network,
including addressing and
traffic control
DATA UNIT Segments
EXAMPLE(S) TCP, UDP
Reliable transmission of
data segments between
points on a network,
DATA UNIT Data
EXAMPLE(S) RPC, PAP
Exchange of info via
multiple back-and-forth
transmissions between
two nodes
DATA UNIT Data
Translation of data
between a networking
service and an application
(e.g., ASCII encoding)
DATA UNIT Data
EXAMPLE(S) HTTP, FTP,
Telnet
High-level APIs, with
resource sharing, file
access, directory services
and virtual terminals