User Datagram Protocol is the simplest communication protocol that is used by TCP/IP suite.

It provides the communication at the minimum expense.

In UDP there is no acknowledgement mechanism by the receiver this means that no confirmation of packet delivery is being sent to the sender by the receiver.

There are more chances to packet loss in this kind of protocol.This is a major problem associated with this protocol  which makes it unreliable.

UDP is known to be unreliable protocol but it use the IP service which itself is the best delivery mechanism in the TCP/IP protocol suite.

• UDP is used when acknowledgement of data does not hold any significance.

• UDP is good protocol for data flowing in one direction.

• UDP is simple and suitable for query based communications.

• UDP is not connection oriented.

• UDP does not provide congestion control mechanism.

• UDP does not guarantee ordered delivery of data.

• UDP is stateless.

• UDP is suitable protocol for streaming applications such as VoIP, multimedia streaming.

UDP Header

UDP application

Here are few applications where UDP is used to transmit data:

• Domain Name Services

• Simple Network Management Protocol

• Trivial File Transfer Protocol

• Routing Information Protocol

• Kerberos