Packet loss

Packet loss occurs when one or more packets of data traveling across a computer networking fail to reach their destination. Packet loss can be caused by a number of factors, including signal degradation over the network medium, oversaturated network links, corrupted packets rejected in-transit or faulty networking hardware.

Lost or dropped packets can result in highly noticeable performance issues or jitter with Streaming Technologies, Voice Over IP, Online Gaming and Videoconferencing, and will affect all other network applications to a degree.

Some network transport protocols such as TCP provide for reliable delivery of packets. In the event of packet loss, the receiver asks for retransmission or the sender automatically resends any segments that have not been acknowledged. Although TCP can recover from packet loss, retransmitting missing packets causes the throughput of the connection to decrease. This drop in throughput is due to the sliding window protocols used for acknowledgement of received packets. In some protocols, if a transmitted packet is lost, it will be resent along with every packet that had been sent after it. This retranmission causes the overall throughput of the connection to drop.

Protocols such as UDP provide no recovery for lost packets. Applications that use UDP are designed to handle this type of packet loss.