Networking Technology: TCP vs UDP

TCP is a type of Internet Protocol (IP) traffic and so is UDP. There are some key differences between the two which should be taken into account when deciding which Internet protocol to opt for.

Here’s a summarized comparison of the two to help you understand the differences better:

Acronym Transmission Control Protocol User Datagram Protocol
Definition It is a connection-oriented protocol requiring two devices to form a connection before transferring data back and forth and closing the connection once the data transfer had been completed. It is a datagram-oriented protocol not requiring devices to form, maintain or close a connection for the data transfer.
Speed Slower than UDP since there is more overhead involved. Faster than TCP since this IP doesn’t undertake any overheads.
Weight Heavyweight; to ensure reliability and control congestion, more packets are required to setup a connection. Lightweight; since messages aren’t tracked or sent in any particular order, it is easily designed.
Order of Data TCP communicates data in the correct order. UDP doesn’t care about the order of the data packets while transferring them.
Reliability TCP assures the sender that all the data sent is received and in the order it was meant to be communicated in. UDP provides no guarantee that all the data sent is received or received in the correct order.
Checking for Errors TCP checks data for errors, and performs error recovery as well. It will resend a data packet with that displays errors. UDP will not check transmitted data for errors and will just get rid or it.



Function TCP is used to transfer data from one device to another over the Internet. UDP is also used to transfer data, however it is a one-time transfer not requiring a connection.
Uses TCP is ideal for transfer of data packets requiring reliability and not having a time constraint. UDP is deal for transferring data packets where quick and efficient transfer is more important than reliability.
Application Web browsing, emails and file transfers are common examples of TCP usage. UDP is often used in Voice over IP, Trivial file transfer, online gaming and Domain name system.

How does TCP work?

A TCP connection is aa three-stage process. It involves the sender initiating a connection and a receiver acknowledging the connection. This is followed by the data being transferred from the sender to the receiver. Finally, once the data transfer is complete, the last stage is terminating the connection.

How does UDP work?

UDP is much simpler than a TCP connection. It does not involve and handshaking or acknowledgement by the receiver. It also does now include error recovery. By removing all these overheads, it provides a faster data transfer procedure.

Advantages and Disadvantages of TCP

TCP is great to allow you to communicate between different types of computers while operating independently of the operating system. It ensures data transfer in the exact order the sender intends. Furthermore, it identifies any errors during the data transfer process and retransmits data if an error is detected.

On the other hand, due to the three-step process of TCP, it is a heavy-weight connection meaning that data transfer via TCP does take significantly longer than UDP. It has a lot of extra features which may unnecessarily eat up your bandwidth.

Advantages and Disadvantages of UDP

UDP involves very little overhead and therefore allows small transactions and also allows data transfer to happen very quickly. It does not involve any handshake protocols. For these reasons, it is supportive of bandwidth-intensive applications while transmitting data in bulk.

However, there is a very high chance of data loss when sending data via UDP since there is no error detection. Data is also not retransmitted if there has been an error or collision takes place. The sender or receiver will receive no notification of the data packet not being delivered either.

TCP vs UDP for OpenVPN

When it comes to OpenVPN, many people wonder whether TCP or UDP is a more suitable protocol. Note that OpenVPN is mainly used for virtual private networks. For these connections, both TCP and UDP offer advance security and privacy. Still, there are a few things that can make you choose one over the other.

If you’re looking for a fast connection and can do without some packets, go for UDP. But its counterpart offers more reliability to VPN users. That said, both are equally secure from surveillance and hacking threats. TCP is the protocol of choice if you’re looking to connect to a P2P network, download files, or browse the web.


It’s important to note that both TCP and UDP have their advantages and disadvantages. However, when deciding which Internet Protocol to use, pick the one which best matches your data transfer needs.