Packet loss

Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is typically caused by network congestion. Packet loss is measured as a percentage of packets lost with respect to packets sent.

The (TCP) detects packet loss and performs retransmissions to ensure reliable messaging. Packet loss in a TCP connection is also used to avoid congestion and reduces throughput of the connection.

In streaming media and online game applications, packet loss can affect the user experience.

Packet loss is typically caused by network congestion. When content arrives for a sustained period at a given router or network segment at a rate greater than it is possible to send through, then there is no other option than to drop packets. If a single router or link is constraining the capacity of the complete travel path or of network travel in general, it is known as a .

Packet loss can be caused by a number of other factors that can corrupt or lose packets in transit, such as radio signals that are too weak due to distance or multi-path fading (in radio transmission), faulty networking hardware, or faulty network drivers. Packets are also intentionally dropped by normal routing routines (such as Dynamic Source Routing in ad hoc networks, ) and through network dissuasion technique for operational management purposes.

Packet loss can also be caused by a packet drop attack.

Packet loss can reduce throughput for a given sender, whether unintentionally due to network malfunction, or intentionally as a means to balance available bandwidth between multiple senders when a given router or network link reaches nears its maximum capacity.

When reliable delivery is necessary, packet loss increases latency due to additional time needed for retransmission. Assuming no retransmission, packets experiencing the worst delays might be preferentially dropped (depending on the queuing discipline used) resulting in lower latency overall at the price of data loss.

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