Packet loss
From Wikipedia, the free encyclopedia
Packet loss occurs when one or more packets of data traveling across a computer network fail to reach their destination.
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[edit] Causes
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, faulty networking hardware, or normal routing routines.
[edit] Effects
When caused by network problems, 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. However, it is important to note that packet loss does not always indicate a problem. If the latency and the packet loss at the destination hop are acceptable then the hops prior to that one don't matter. [1]
[edit] Packet recovery
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 acknowledgment of received packets. In certain variants of TCP, if a transmitted packet is lost, it will be resent along with every packet that had been sent after it. This retransmission 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.
[edit] See also
[edit] References and notes
[edit] Footnotes
- Packet loss or latency at intermediate hops. (HTTP). Retrieved on 2007-02-25.
- Packet loss practically represented (German) (HTTP). Retrieved on 2007-03-12.
