Packet loss

Packet loss (English packet loss ) occurs in the packet-based data transmission in networks.

There are various causes of packet loss:

• Error of the transmission medium
• Packet loss in the processing / (interim) storage of packages
• Packet loss due to the non-compliance of rules and standards

Packet loss can occur in different layers of the OSI model.

Error of the transmission medium

Does not work as intended, the transmission medium, it is possible that data packets do not arrive at the intended target. This condition is then referred to as packet loss. Reasons for this are often long lines ( too much attenuation of the signal), damaged cables or interference between different lines. The physical characteristics are then disrupted such that the signals at the other end of the line will be interpreted incorrectly or not arrive. If falsified signals received therefrom no longer usable data can often be recovered.

Failure of the transmission medium can be compensated to a certain degree through the use of repeaters ( in case of excessive damping ) by Hamming codes or special transfer process. In the transmission of DSL signals, for example, interleaving is used for this purpose.

Examples of packet loss

• Conscious throwing away ( "DROP " ) of data packets through, for example, a packet filter. The appropriate package will be deleted without further processing.

• Decrease the TTL value of an IP data packet to "0". In this case, the packet is dropped and inform the sender via ICMP packet.

• Goal can not be reached: If a network node can not forward a packet because the route information for the destination lacks, the packet is also discarded. The sender will receive an ICMP packet over it.

• Communication technology