User Datagram Protocol or UDP is one of the main members of the Internet Protocol Suite. By using it, applications can send data messages, often referred to as datagrams, to other hosts on an Internet Protocol (IP) network.
Compared to TCP, UDP is an unreliable and connectionless protocol. This means that there is no need for the sender to establish a prior connection before data transfer. As such, it generally works by sending packets of data directly to a target computer without needing a connection first, indicating the order of the datagrams, or checking whether they arrived as intended.
What is UDP used for?
By not needing a connection before data is transferred, it speeds up communications over the network, and it’s especially helpful for transmissions like video playback or DNS lookups.
It’s used in these applications because dropping data packets is better than waiting for the transmission. In other words, speed is more important than data loss. Because of this, and the fact that voice and video traffic are designed to handle some level of data loss, it’s used in voice and video because they are time-sensitive.
For instance, VOIP, commonly used by many Internet-based telephone services, use UDP for their operations. This is because a real-time phone conversation is preferable to one that is crystal clear but heavily delayed. Also, because of its speed, it is the ideal protocol for online gaming.
Unfortunately, although packet loss is not a significant problem in most cases, UDP can be exploited for malicious purposes, especially in DDoS attacks. UDP can therefore be a security risk in certain instances. In these attacks, attackers can overload a server with UDP traffic without first getting permission to begin communication.
In this instance, a typical UDP attack sends a large number of UDP datagrams to a target computer which forces the target computer to respond with the equally large number of ICMP packets. The computing resources required to respond exhausts the target computer resulting in a denial of service to legitimate traffic.
Why is UDP Important?
UDP is important because it facilitates faster communication on a network between two computers and it has a much lower bandwidth overhead and latency compared to other communication protocols.
As a result, voice and video communication, voice and video playback, DNS lookups and another form of time-sensitive communications would not be as fast as it is today.