Question

WHAT ARE THE DIFFERENCES BETWEEN TCP/IP AND UDP IN TERMS OF OSI LAYERS AND DEFINITION ITSELF?

PLEASE GIVE BREIFE EXPLANATIONS WITH PICTURES AND EXAMPLES WITH EASY ENOUGH TO MEMORIZE AND UNDERSTAND

Answer 1

Definition Of TCP

TCP or Transmission Control Protocol is a connection-oriented protocol, found in the transport layer of the TCP/ IP Model. It establishes a connection between source and destination computer before starting the communication.

It is highly reliable, as it uses the 3-way handshake, flow, error and congestion control. It makes sure that the data sent from source computer are received accurately by the destination computer. If in case, data received is not in the proper format, then TCP retransmits the data.
Following protocols use TCP for transmitting data:

• HTTP(Hypertext Transfer Protocol),
• HTTPs(Hypertext Transfer Protocol Secure),
• FTP(File Transfer Protocol),
• SMTP(Simple Mail Transfer Protocol), etc.

Definition Of UDP

UDP or User Datagram Protocol is a connectionless protocol found in the transport layer of TCP/IP Model. It neither establishes a connection nor checks whether the destination computer is ready to receive or not, it just sends the data directly. UDP is used to transfer the data at a faster rate. It is less reliable and so used for transmitting data such as audio and video files.

UDP neither guarantees the delivery of data nor does it retransmits the lost packets.

Key Differences Between TCP and UDP

1. TCP is Connection-oriented whereas, UDP is Connectionless protocol.
2. TCP is highly reliable for transferring useful data as it takes the acknowledgment of information sent. And resends the lost packets if any. Whereas in the case of UDP if the packet is lost it won’t request for retransmission and a corrupt data is received by the destination computer. So, UDP is an unreliable protocol.
3. TCP is slower as compared to UDP since TCP establishes the connection before transmitting data, and ensures the proper delivery of packets. On the other hand, UDP does not acknowledge whether the data transmitted is received or not.
4. Header size of UDP is 8 bytes, and that of TCP is more than double. TCP header size is 20 bytes since, and TCP header contains options, padding, checksum, flags, data offset, acknowledgment number, sequence number, source and destination ports, etc.
5. Both TCP and UDP can check for errors, but only TCP can correct the error since it has both congestion and flow control.

Comparison Chart

BASIS FOR COMPARISON	TCP	UDP
Meaning	TCP establishes connection between the computers before transmitting the data	UDP sends the data directly to the destination computer without checking whether the system is ready to receive or not
Expands to	Transmission Control Protocol	User Datagram Protocol
Connection Type	Connection Oriented	Connection Less
Speed	Slow	Fast
Reliability	Highly Reliable	Unreliable
Header Size	20 Bytes	8 Bytes
Acknowledgement	It takes acknowledgement of data and has the ability to re transmit, if the user requests.	It neither takes acknowledgement nor it re transmits the lost data.