Packet loss

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Packet loss (engl. Packet loss ) occurs in the packet-based data transmission in computer networks and communication networks on.

There are several causes of packet loss:

  • Transmission medium error
  • Loss of packets during processing / (temporary) storage of packets
  • Packet loss due to non-compliance with rules and standards

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

Transmission medium error

If the transmission medium does not work as intended, it is possible that data packets will not arrive at the specified destination. This condition is called packet loss. This is often caused by cables that are too long (too much attenuation of the signal ), damaged cables or interference between different cables. The physical characteristics are then so disturbed that the signals at the other end of the line are incorrectly interpreted or do not arrive at all. If corrupted signals are received, usable data can often no longer be obtained.

To a certain extent, errors in the transmission medium can be compensated for by using repeaters (if the attenuation is too high ), by Hamming codes or special transmission methods. When transmitting DSL signals, z. B. Interleaving used.

Examples of packet loss

  • Deliberate throwing away ("DROP") of data packets by e.g. B. a packet filter . The corresponding package will be deleted without further processing.
  • Destination not reachable: If a network node cannot forward a packet because it lacks the route information for the destination, the packet is also discarded. The sender is informed of this via an ICMP packet.

literature

  • Jonathan Davidson, James Peters: Voice over IP Basics. Markt + Technik Verlag, Munich 2000, ISBN 3-8272-5800-6 .
  • Andres Keller: "Data transmission in the cable network". Springer Verlag, Berlin / Heidelberg 2005, ISBN 3-540-22501-3 .
  • Florian Jomrich: Seamless handover in wireless vehicle communication networks. Springer Fachmedien, Wiesbaden 2016, ISBN 978-3-658-13300-9 .
  • James F. Kurose, Keith W. Ross: Computer Networks. The top-down approach, 4th edition, Pearson Studium, Munich 2008, ISBN 978-3-8273-7330-4 .
  • Sigurd Schobert: Protocol analysis in local networks. Part 1, Expert Verlag, Renningen 1994, ISBN 3-8169-1149-8 .