In this blog we are going to talk about the protocols. you must be wondering what exactly is protocols?
protocols is nothing but just a fancy name of rules.
In simpler terms, Protocol is a set of some agreed rules based on that two system communicate with each other. without these rules we can’t communicate reliably.
Why we need protocols?
- Because without these rules or protocols internet don’t know where or whom to send the data. these protocols help us to address the reciever and sender so the communication between them can be as smooth as possible without worring about the reliablility
TCP (Transmission-Control-Protocol)
it is a protocol that allows devices to communicat reliably over a network. it ensures that data reaches the destination correctly ans in the right order, even if part of the network are slow or less reliable.
TCP establishes a logical connection between the sender and receiver before data transmission begins.
It ensures that data is delivered accurately and in the same order in which it was sent using acknowledgements and sequence numbers.
Before sending any data it establishes a connection between sender and reciever for secure and reliable data transfer and the process that is used by it is called 3-Way handshake and also the proccess which it used to terminate the connection is known as 4-Way handshake
How TCP works?
3-Way Handshake → Before sending any data TCP establishedd a connection between client and server for secure and reliable data transfer.
Segmenting → When an application sends data (like an email) , TCP breaks that data into small chunks called segments. this makes it easier to send large amount of data over the network reliably, Each segment has header containing information like sequence number, ports and flags. it looks like this:
Routing via IP → once TCP creates segments of data they are handed to IP and IP is responsible for delievering the segments from the client to the server.
Acknowladgments (ACKs) → the reciever(client) sends an ACKs for every segment and this tells the sender that data has arrived safely , Suppose if ACKs is not revieved , TCP assumes that the segment was lost and triggers retransmission.
Retransmission → if sender doesnt recieve an acknowledgment within a certain time then it resends the missing segment, This ensures no data is lost making TCP reliable.
Flow & Error Control →
Flow Control : TCP prevents the sender from sending too much data too quickly for the server to handle.
Error Control :TCP checks for corrupt segment using checksums and request transmission if needed.
Together, these mechanisms ensure data is delivered reliably and efficiently, without overloading the network or the receiver
UDP (User-Datagram-Protocol)
UDP is a protocol that provides fast, connectionless and lightweight communication between processes.
it doesn’t guarantee delivery, order or error checking making it suitable for real-time and time-sensitive application such as video streaming,audio call, gaming or live streaming.
UDP Header
How TCP and UDP are different from each other
When to use TCP?
TCP can be used in the following scenarios
Text Communication → We know we cannot tolerate any discrepeancy in texting between sender and reciever. Hence we have to use the protocol which is reliable that’s why we prefer TCP.
Transfer of files or FTP → TCP is used in File transfer when we cannot tolerate the loss of data and receiving the data incorrect order is of utmost importance.
HyperText Transfer Protocol → Since TCP provides use inorder data, error control and flow control that why it is prefer while accessing the web pages.
When to use UDP?
Real-Time Application → Because UDP reduces the latency , which is crucial for real-time application such as video streaming or online gaming
Broadcast and Multicast Transmission → it supports broadcast and multicast sending capabbilities inherently, allowing information to be sent to multiple recievers easily and quickly, useful in the scenarios like updating live statistics on a sports website.
High-Speed Data Transfer → UDP is suitable for scenarios where the volume of data is enormous, and retransmission overhead is not acceptable, such as in certain file transfer applications.
Real World Analogy TCP vs UDP
TCP : Courier Service
Imagine you send important document using courier service , then what happens? you get a tracing number, the reciever must have to sign after delievery, if page is missing then it is resent, page arrive in correct order.
this whole process exactly explains how TCP works.
Now Imagine it like this :
Courier recepit → TCP acknowledgment
Re-sending lost pages → Retransmission
Proper order → Sequencing
→ TCP used when accuracy matters more than speed
UDP : Phone call
Imagine you are talking on a phone call , then what happenens? if you missed a word then speaker dosen’t repeat, conversation continues wihtout waiting , speed matters more than perfection
This is how UDP works.
Now Imagine it like this :
No conformation → No acknowledgment
Missed word → lost packets
Real-time flow → low latency
→ UDP used when speed matters more than accuracy
What is HTTP and where it fits
HTTP (Hypertext Transfer Protocol) is a core internet protocol that defines how data is exchangesd between client and server on the web.
- Enables communication between web browsers and web servers
- forms the foundation of data transfer on the World wide web.
- Defines rules for requesting and delivering data between system
[ref of image : GeekforGeeks]
Note : it is an application-layer protocol used implicitly by web browser to transfer text, images and multimedia accross distributed , hypermedia-based web systems.
Common confusions →
Are HTTP and TCP same?
Answer is No, TCP is transport layer protocol which is responsible for reliable data delievry , ensuring data packets arrive in order, without packet loss. whereas HTTP is an application layer protocol , it defines how web data is requested and sent such as web pages, forms and APIs
infact HTTP depends on TCP. because HTTP uses TCP to safely send it’s request and response but it does not handle reliability itself.
In simpler terms TCP handles how data travels , while HTTP handles what the data means
Are they work on the same layer?
- Answer is again No. TCP works on transport layer where as HTTP works on Application layer
Relationship between TCP and HTTP →
As we know TCP and HTTP both works on different layers , and we also know that HTTP requires TCP , then the main question arises is How they interact?
- So, TCP first creates a reliable connection between client and server then HTTP sends request and responses through that TCP connection, while TCP ensure that HTTP data is delievered safely and completely
HTTP relies on TCP for reliable communication while TCP does not understand or depend on HTTP
This is the Core relaionship between TCP and HTTP.
Hope you enjoyed reading ❤️
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