when computer was invented, we don;t have network. computer was a stand-alone machine to perform calculation

The TCP/IP suite is all of different protocols and port and TCP/UDP protocols that we use to make up the internet, so that our computer can talk to other computer around the world

In Application layer: HTTP: work with receiving and downloading webpages information. Our internet browser is also an application

The UDP is connectionless communication protocol

ARP: Address resolution control: is how our computer find out which MAC address associated with which IP address. ARP is in data link layer (layer 2)

DNS: Domain name system

Port: is communication endpoints for our connections to our computers [from wikipedia] In the internet protocol suite, a port is an endpoint of communication in an operating system. While the term is also used for female connectors on hardware devices (see computer port), in software it is a logical construct that identifies a specific process or a type of network service.

A port is always associated with an IP address of a host and the protocol type of the communication, and thus completes the destination or origination network address of a communication session. A port is identified for each address and protocol by a 16-bit number, commonly known as the port number. For example, an address may be "protocol: TCP, IP address:, port number: 80", which may be written when the protocol is known from context. Transport layer protocols, such as the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP), specify a source and destination port number in their headers. A port number is a 16-bit unsigned integer, thus ranging from 0 to 65535

Port numbers are sometimes seen in web or other uniform resource locators (URLs). By default, HTTP uses port 80 and HTTPS uses port 443, but a URL like http://www.example.com:8080/path/ specifies that the web browser connects instead to port 8080 of the HTTP server.


FTP: FILE transfer protocol Because TCP is connection oriented , and make sure that we have connection to our endpoint first, and then start sending the file. TCP also make sure that our file get there and not corruped and in the right order => there are no encoding/overhead in FTP. => so FTP is insecure FTP is port 21/TCP

TFTP: Trivial FTP: send to multiple clients port 62: UDP

SFTP: secure FTP: => TCP :port 22 encrypt our data using SSH more secure than FTP

Mail protocol:

SMTP: Simple mail transfer protocol allow us to send email from the clients, such as Outlook to a server, and allow the server to send emails between each other

e.g: Outlook -> send emails to Microsoft -> to Yahoo.

HTTP: port80: TCP hyper text transfer protocol

HTTPs: encrypted http: port 443: TCP certificate between clients/server => certificate: a piece of information or data that we use to encrypt our traffic between us and the server.

Telnet: Remote terminal connection: port 23 UDP/TCP unencrypted

SSH: encrypted connection between points : port 22: TCP

*RDP: port 3389 : TCP/UDP: Remote Desktop protocol In internal environment, we need to intiate the Remote desktop connection between clients but we may not want some one outside the organization attemp to initiate RDP. We can set up firewall, DMZ, internal firewall able to block RDP connection

*SNMP: simple network management protocol: this is a device allow us to manage devices over IP: port: 161 Agent 162:Manage