Services, Ports and Protocols
Before heading towards the blog, I would recommend you to have a basic knowledge of Networking models like TCP/IP Models so that it would become familiar to understand these terms.
Protocols — Protocols in a network can be defined as the set of standards that need to be followed in a simple information exchange process in a network.
Network Protocols assure the transparency of data that is being sent over the network. Without having protocols, data exchange would become very complicated to understand for someone.
Some of the standard organizations have earlier set up some protocols for a network.
Some of the protocols are:-
TCP: Also referred to as Transmission Control Protocol, is a very basic and must protocol for a network that breaks the data or messages into small packets so that they can be transferred in a small amount with low latency and at the other destination point, this protocol helps to reassemble the small packets into single data.
UDP: Also referred to as User Datagram Protocol, is also an important protocol that is generally used when a client wants quick transfer of data and minimum complications in its requests.
NOTE- For example, TCP is used in sending messages over the network so that the message doesn’t get messed up while UDP is generally used in watching videos for continuous playback of video keeping ignorance in the video quality.
IP: Internet Protocol, used with TC-Protocol for sending the message to the assigned nodes over a network through the help of IP addresses.
SMTP: Known as a simple mail transfer protocol, is referred mainly for sending mail requests.
POP3: Known as Post Office Protocol which is specifically referred for receiving mail requests.
HTTP/HTTPS: HyperText Transfer Protocol/ HyperText Transfer Protocol Secure- these protocols are meant for creating server requests and to make requests which contain HTML tags and links.
These HTTP requests are generated between clients and servers.
The difference between HTTP and HTTPS exists in the case of encryption. HTTP is unsecured as it doesn’t have encryption while HTTPS has.
ARP: Address Resolution Protocol is an interesting protocol that is used for retrieving physical addresses like MAC Addresses via sending ARP requests containing dynamic IP addresses.
Ports
To understand this, let’s take an example!!
How would you enter a restaurant to get food or any other complex, You would be using a gate as a medium to enter these places. The same exists for a device in which there is the number of ports in a device where there are different services is going on or we can say each port is dedicated to different services.
There are a total of 65,535 Ports available for a system. The division of the ports can be justified as followed:
0–1023 — This range is the most used range which contains all common ports that are being used for different services
1024–49151 — These ports are reserved for specific services.
49152–65535 — This range of ports is used for a use-and-throw purpose, they are used when a session starts and end up immediately when a session ends.
Services running on Ports
Services running on ports over a network can be defined as different functionalities running in a system.
Some of the very common services running on ports are listed below:
PORT SERVICE
20 FTP
21 FTP
22 SSH
25 SMTP
80 HTTP
53 DNS
443 HTTP over SSL
1433 SQL