Differences Between TCP and UDP

Key Difference between TCP vs UDP

TCP is a connection-oriented protocol, whereas UDP is a connectionless protocol.
The speed of TCP is slower, while the speed of UDP is faster.
TCP uses handshake protocols like SYN, SYN-ACK, and ACK, while UDP uses no handshake protocols.
TCP does error checking and also makes error recovery. On the other hand, UDP performs error checking, but it discards erroneous packets.
TCP has acknowledgment segments, but UDP does not have any acknowledgment segments.
When we compare TCP vs. UDP protocols, TCP is heavy-weight and UDP is lightweight.

Here, I have analyzed the difference between the TCP and UDP and will comprehensively evaluate their pros and cons.

What is TCP?

TCP/IP helps you to determine how a specific computer should be connected to the internet and how you can transmit data between them. It helps you to create a virtual network when multiple computer networks are connected.

TCP/IP stands for Transmission Control Protocol/Internet Protocol. It is specifically designed as a model to offer a highly reliable and end-to-end byte stream over an unreliable internetwork.

How does TCP work?

A TCP connection is established with the help of a three-way handshake. It is a process of initiating and acknowledging a connection. Once the connection is established, data transfer begins, and when the transmission process is finished, the connection is terminated by the closing of an established virtual circuit.

Features of TCP

From my personal experience, here are some critical features of TCP:

Delivery Acknowledgements
Re transmission
Delays in transmission when the network is congested
Easy error detection

Applications of TCP

Here are the applications of TCP that I have worked with:

It helps you establish or set up a connection between different types of computers.
Operates independently of the operating system
Supports many routing protocols.
It enables internetworking between the organizations.
It can be operated independently.
Supports several routing protocols.
TCP can be used to establish a connection between two computers.

Advantages of TCP

Here are the pros of TCP from my extensive personal experience:

It helps you establish or set up a connection between different types of computers.
It operates independently of the operating system.
It supports many routing protocols.
It enables internetworking between the organizations.
The TCP/IP model has a highly scalable client-server architecture.
It can be operated independently.
Supports several routing protocols.
It can be used to establish a connection between two computers.

Disadvantages of TCP

From my experience, here are the disadvantages of using TCP:

TCP never concludes a transmission without all data in motion being explicitly asked.
You can’t use it for broadcast or multicast transmission.
TCP has no block boundaries, so you need to create your own.
TCP offers many features that you don’t want. It may waste bandwidth, time, or effort.
In this model, the transport layer does not guarantee the delivery of packets.
Replacing protocol in TCP/IP is not easy.
It doesn’t offer clear separation from its services, interfaces, and protocols.

What is UDP?

UDP is a Datagram-oriented protocol. It is used for broadcast and multicast types of network transmission. The full form of UDP is User Datagram Protocol (A datagram is a transfer unit associated with a packet-switched network.) The UDP protocol works almost similarly to TCP, but it throws all the error-checking stuff out, all the back-and-forth communication and deliverability.

How does UDP work?

UDP uses a simple transmission method without implied hand-shaking dialogues for ordering, reliability, or data integrity. UDP also assumes that error checking and correction are not important or performed in the application to avoid the overhead of such processing at the network interface level. It is also compatible with packet broadcasts and multicasting.

Features of UDP

Here are some important features of UDP that we’ve identified:

Supports bandwidth-intensive applications that tolerate packet loss.
Less delay
It sends a bulk quantity of packets.
Possibility of data loss
Allows small transactions (DNS lookup)

Applications of UDP

Here are the applications of UDP that I have utilized:

The UDP method is largely used by time-sensitive applications as well as by servers that answer small queries from a larger client base.
UDP is compatible with packet broadcasts for sending all over the network and for multicasting sending.
It is also used in domain name systems, voice over IP, and online games.

Advantages of UDP

From what I’ve seen working with UDP, here are the pros of UDP:

It never restricts you to a connection-based communication model; that’s why startup latency in distributed applications is low.
The recipient of UDP packets gets them unmanaged, which also includes block boundaries.
Broadcast and multicast transmissions are also available with UDP.
Data loss can occur.
Small transaction (DNS lookup)
Bandwidth-intensive app that endures packet loss

Disadvantages of UDP

Here are the cons and drawbacks of UDP, based on my observations:

In the UDP protocol, a packet may not be delivered or delivered twice. It may be delivered out of order, so you get no indication.
Routers are quite careless with UDP, so they never retransmit it if it collides.
UDP has no congestion control or flow control, so implementation is the job of a user application.
UDP mostly likes to suffer from worse packet loss.

Difference between TCP and UDP

Having worked closely with these protocols, I can outline the main differences between UDP and TCP:

TCP	UDP
It is a connection-oriented protocol.	It is a connectionless protocol.
TCP reads data as streams of bytes, and the message is transmitted to segment boundaries.	UDP messages contain packets that were sent one by one. It also checks for integrity at the time of arrival.
TCP messages make their way across the internet from one computer to another.	It is not connection-based, so one program can send lots of packets to another.
TCP rearranges data packets in a specific order.	The UDP protocol has no fixed order because all packets are independent of each other.
The speed for TCP is slower.	UDP is faster as error recovery is not attempted.
The header size is 20 bytes.	The header size is 8 bytes.
TCP is heavy-weight. TCP needs three packets to set up a socket connection before any user data can be sent.	UDP is lightweight. There are no tracking connections, ordering of messages, etc.
TCP does error checking and also makes error recovery.	UDP performs error checking, but it discards erroneous packets.
Acknowledgment segments	No acknowledgement segments
Using handshake protocols like SYN, SYN-ACK, and ACK	No handshake (so connectionless protocol)
TCP is reliable as it guarantees the delivery of data to the destination router.	The delivery of data to the destination can’t be guaranteed in UDP.
TCP offers extensive error-checking mechanisms because it provides flow control and acknowledgement of data.	UDP has just a single error-checking mechanism, which is used for checksums.

How to Choose Between a TCP and a UDP

Now, we will explore how the TCP and UDP protocols stack up against each other.

TCP is an ideal choice for us, and even though it has associated overhead when most of that overhead is in the connection, we find that our application stays connected for any length of time.
UDP is ideal for use with multimedia like VoIP.
Use TCP sockets when both client and server independently send packets at that time; an occasional delay is acceptable. (e.g., online poker).
You should use user UDP if both client and server may separately send packets, and occasional delay is also not acceptable. (e.g., multiplayer games).