4.2: EXPLAIN APPLICATION LAYER PROTOCOLS - Coggle Diagram
4.2: EXPLAIN APPLICATION LAYER PROTOCOLS
4.2.1 EXPLAIN HOW THE FUNCTIONS OF THE APPLICATION LAYER,SESSTION LAYER, AND PRESENTATION LAYER WORK TOGETHER TO END USER APPLICATION. (LYIANA & MELLISSA)
Application Layer (Mellissa)
Closest to the end user.
Used to exchange data between programs running on the source and destination hosts.
Presentation and Session Layer (Mellissa)
Presentation Layer functions:
Formatting data at the source device into a compatible form for the receiving device.
Session Layer functions:
To create and mantain dialogs between source and destination applications.
Client-Server Model (LYIANA)
:check: Client and server processes are considered to be in the applicationlayer. :check:Application layer protocols describe the format of the requests and responses between clients and servers.
:check: EXAMPLE :is using and ISP's email service to send,receive and store email.
TCP/IP Application Layer Protocols (Mellissa)
Domain Name Server (DNS) TCP, UDP 53
translates domain names, such as cisco.com into IP addresses
(BOOTP) - Bootstrap Protocol
is being superseded by DHCP
Dynamic Host Configuration Protocol (DHCP) UPD client 98, server 67:
Dynamically assigns IP addresses to client stations at start-up
Simple Mail Transport Protocol (SMTP) TCP 25
enables clients to send email to a mail server
Post Office Protocol (POP) TCP 110
enables clients to retrieve email from a mail server
Internet Message Access Protocol (IMAP) TCP 143
enables clients to retrieve email from a mail server, maintains emails on server
File Transfer Protocol (FTP) TCP 20 and 21
is a reliable, connection-oriented and acknowledged file delivery protocol
Trivial File Transfer Protocol (TFCP) UDP 69
is a simple connectionless file transfer protocol
Hypertext Transfer Protocol (HTTP) TCP 80, 8080
is a set of rules for exchanging text, graphic images, etc. on the World Wide Web
Hypertext Transfer Protocol Secure (HTTPS) TCP, UDP 443
uses encryption and authentication to secure communication
Peer-to-Peer Networks (LYIANA)
:check: Data is accessed from a peer device without the use of a dedicated server.
:check: Each device (know as a peer) can function as both a server and a client.
Peer-to-Peer Applications (LYIANA)
:check: Allows a device to act as both a client and a server within the same communication.
:check: require that each end device provide a user interface and run a background service.
Common P2P Applications (LYIANA
Common P2P network include:
:check: Some P2P application are based on the Gnutella protocol, where each user shares whole files with other users.
:check: Many P2P applications allow users to share pieces of many files with each other at the same time- this is BitTorrent technology.
4.2.2 EXPLAIN HOW WEB AND EMAIL PROTOCOLS OPERATE.
(Flaveen Nicholas Dominic)
Hypertext Transfer Protocol and Hypertext Markup Language
When a web address or uniform resource locator (URL) Is typed into a web browser, the web browser establishes a connection to the web service running on the server, using the HTTP protocol.
HTTP is a type of request/response protocol and there are three common HTTP message types
GET - A client request for data
POST - Uploads data files to the web server
PUT - Uploads resources or content to the web server
A protocol that uses encryption and authentication to secure data.
Email clients communicate with mail servers to send and receive email. Mail servers communicate with other mail servers to transport messages from one domain to another. There are three protocols for the email.
Simple Mail Transfer Protocol (STMP)
Post Office Protocol (POP)
Retrieve email from a mail server. The email is downloaded from the server to the client and then deleted on the server.
Internet Message Access Protocol (IMAP)
This protocol has the same function as the POP but this protocol downloads the copies of messages from the original messages and are stored on the server.
File Transfer Protocol
This protocol requires two connections between the client and the server, one for the commands and replies while the other for the actual file transfer.
The client establishes the first connection to the server for control traffic using a TCP port 21.
Then, the client establishes the second connection to the server for the actual data transfer using TCP port 20.
Server Message Block
The SMB is a type of client/server file sharing protocol.
SMB file-sharing and print services have become a 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.
4.2.3 EXPLAIN HOW DNS AND DHCP OPERATE.(SYAIRUL)
IP ADDRESSING SERVICES
Domain Name Service
Convert the numeric address into a simple,recognizable name.
Defines an automated service that matches resource names with the required numeric network address
When A Client makes a query the server DNS process first look at its own records to resolve the name
If unable,It contacts other servers to resolve the name.
The server temporarily stores the numbered address in the event that the same name is requested again
The ipconfig/displaydns command displays all of the cached DNS entries on a windows PC
a utility that allow a user to manually query the name server to resolve a given host
Dynamic Host Configuration Protocol
The Dynamic Host Configuration Protocol for IPv4 automates the assignment of IPv4 addresses,subnet masks,gateways and other parameters.
DHCP-distributed addresses are leased for a set period of time, then returned to pool for reuse
Usually employed for end user device.Static addressing is used for network devices, such as gateways, switches ,servers and printers
DHCPv6 (DHCP for IPv6) provides similar services for IPv6 clients