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5.2 Explain Application Layer Protocols - Coggle Diagram
5.2 Explain Application Layer Protocols
Explain the functions of each layer and how they work together to provide network services to end user applications
Application, Presentation and Session
Presentation Layer
◦ Formatting data at the source
device into a compatible form
for the receiving device.
◦ Compressing data.
◦ Encrypting data.
Session Layer Function
◦ Create and maintain dialogs
between source and
destination applications.
Application Layer
◦ Closest to the end
user.
◦ Used to exchange data
between programs
running on the source
and destination hosts.
TCP/IP Application Layer Protocols
Domain Name Server (DNS) TCP,UDP 53 -
Translates domain names, such as cisco.com, into
IP addresses.
◦ (BOOTP) – Bootstrap Protocol - BOOTP is being
superseded by DHCP.
◦ Dynamic Host Configuration Protocol (DHCP) UDP
client 68, server 67 – Dynamically assignsIP
addresses to client stations at start-up.
◦ Simple Mail Transport Protocol (SMTP) TCP 25 -
Enables clients to send email to a mail server.
How Application Protocols Interact with End-User Applications
Client-Server Model
Peer-to-Peer Networks
Peer-to-Peer Applications
Common P2P Applications
◦ G2
◦ Bitcoin
◦ BitTorrent
◦ eDonkey
Explain how web and email
protocols operate
HTTP and HTTPS
HTTP is a request/response
protocol.
Three common HTTP message
types are:
◦ GET - A client request for
data.
◦ POST - Uploads data files to
the web server.
◦ PUT - Uploads resources or
content to the web server.
HTTP Secure (HTTPS) protocol
uses encryption and
authentication to secure data.
Email Protocols
Simple Mail Transfer Protocol
(SMTP) to send email.
Post Office Protocol (POP) to
retrieve email.
Internet Message Access Protocol
(IMAP) to retrieve email.
File Transfer Protocol
FTP requires two connections
between the client and the server,
one for commands and replies, the
other for the actual file transfer:
◦ The client establishes the first
connection to the server for
control traffic using TCP port 21.
◦ The client establishes the
second connection to the server
for the actual data transfer
using TCP port 20.
Server Message Block
The Server Message Block (SMB) is
a client/server file sharing protocol:
◦ SMB file-sharing and print
services have become the
mainstay of Microsoft
networking.
◦ Clients establish a long-term
connection to servers and can
access the resources on the
server as if the resource is local
to the client host.
Explain how Domain Name
System (DNS) and Dynamic Host
Configuration Protocol (DHCP)
operate
Domain Name Service
Domain names convert the
numeric address into a
simple, recognizable name.
The DNS protocol defines
an automated service that
matchesresource names
with the required numeric
network address.