UDP does not have built-in mechanisms to deal with network congestion. When congestion occurs, UDP simply continues to send packets at the same rate, potentially exacerbating the problem. This is because UDP does not have a mechanism for detecting or responding to congestion signals, such as dropped packets or increased delays.
As a result, applications using UDP are responsible for managing congestion control on their own, which can be more challenging than with protocols like TCP that have congestion control built-in. Applications can employ various techniques to deal with congestion, such as adjusting the rate at which they send packets, reducing the size of packets, or prioritizing certain types of traffic.
