Difference Between TCP vs UDP
The following article provides an outline for TCP vs UDP. TCP is link-oriented, and UDP is connection-free. TCP links the transmitter to the receiver until data can be transmitted. Until transmitting data, UDP does not create a connection. TCP is trustworthy. The receiver is expected to receive data transmitted via a TCP protocol. It will retrieve data and send back data if data is lost in transit. TCP will also monitor error packages and track packages in order to prevent data from being lost or corrupted.
What is TCP?
TCP stands for Transmission Control Protocol. TCP is a connection-oriented protocol, i.e., it provides a process to process (end to end) communications. The transmission control protocol is used to show the relation between other protocols lies in the TCP/IP protocol. It is an intermediary between the application program and network operations as it lies between the application and network layers. TCP delivers data or messages in the form of packets. TCP provides different features like sequence number, flow control, error control, acknowledgment number, congestion control, etc., to ensure that the packet being delivered cannot be affected by other activities.
What is UDP?
UDP stands for User Datagram protocol. It is used to send a small message from one host to another. It is a connectionless protocol, i.e., transferring data from one end to another; there is no need for connection establishment. UDP also lies between the application layer and the network layer. It also delivers data or information in the form of packets; these packets are called user datagrams. UDP uses multiplexing to handle the outgoing user datagrams from multiple processes and demultiplexing to handle the incoming user datagrams that go to different processes on the same host.
Head to Head Comparison Between TCP vs UDP
Below is the list of the top 11 differences between TCP vs UDP:
Key Difference Between TCP vs UDP
Let us discuss some of the major key differences between TCP vs UDP:
- One of the main key differences between TCP and UDP is TCP is connection-oriented, and UDP is connectionless. To transfer data, TCP must establish a connection with other hosts.
- TCP uses sequence numbers for numbering the packets during the transmission of data. So that at the receiver site, data can be collected sequentially using sequence numbers. While UDP does not use sequence numbers for numbering the packets, so it is difficult.
- TCP provides a flow control service to handle the receiving data’s overflow, while UDP does not provide a flow control service.
- TCP provides reliable services, while UDP does not provide reliable services.
- In TCP, retransmission of the segment occurs through the window mechanism. Since there is no window mechanism in UDP, it does not support the retransmission of the datagram.
- In TCP, the acknowledgement number is given to the segment, while in UDP, the acknowledgement number is not used for datagrams.
- TCP is linked, while UDP is connection-free. This means that TCP tracks all transmitted data, requiring (usually) acknowledgement per byte. UDP is usually used on protocols where a few lost datagrams don’t matter. It doesn’t use any accreditation. TCP is a secure information transfer protocol because of its acknowledgements. It guarantees that no information is sent to the top layer application, which is not in order, duplicated or lacking parts.
- TCP provides services such as Process to process communication, stream delivery service, flow control, error control, congestion control, full-duplex communication, multiplexing, demultiplexing, acknowledgement number, system number, sequence number and byte number, Whereas UDP has features like Process to process communication, multiplexing, and demultiplexing along with Encapsulation, decapsulation.
- TCP has features such as flow control using sliding windows, window sides adjustment heuristic, and congestion avoidance algorithms to manage data flow. Whereas UDP does not provide features to manage the data flow.
- Data Quality Sustainability is great in TCP as compared to UDP because it can manage small to very large data, while UDP can manage small to moderate amounts of data.
Comparison Table of TCP vs UDP
The table below summarizes the comparisons between TCP vs UDP:
Points |
TCP |
UDP |
Full Form | TCP stands for Transmission Control Protocol. | UDP stands for User Datagram Protocol. |
Protocol | TCP is connection-oriented. | UDP is connectionless. |
Packet Format | Packets in TCP is called a segment. | Packets in UDP are called user datagrams. |
Header Size | TCP header is 8 bytes. | UDP header is 20 to 60 bytes. |
Acknowledgment | As TCP is a connection-oriented service, it sends an acknowledgement when all the data is delivered. | UDP does not send an acknowledgement when data delivery is done because it is a connectionless service. |
Error Control Mechanism | TCP support an error control mechanism. | There is no error control mechanism in UDP except for checksum. |
Process to Process Communication | It provides a process to process communication using port numbers. | It provides the process to process communication using the combination of port numbers and IP addresses. |
Transmission Speed | The transmission speed of the packet is low. | The transmission speed of the packet is high. |
Services | The process to process communication, stream delivery service, reliable service, flow control, error control, congestion control, full-duplex communication, multiplexing, demultiplexing, acknowledgement number, system number, sequence number, and byte number. | The process to process communication, Encapsulation, decapsulation, multiplexing, and demultiplexing. |
Reliability | More reliable. | Moderately reliable as compared to TCP. |
Window Mechanism | In TCP, the window mechanism Is there. | In UDP, there is no window mechanism. |
Conclusion
In this article we have seen what is TCP and UDP, head to head comparison and key differences between them.

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