What is Packet Loss?

Introduction

When using diagnostic tools such as ping or traceroute, you may have noticed a term being used called "packet loss." This is an important metric that shows whether or not all your packets have made it to the destination server; any value greater than zero (>0%) is an indicates that a packet has been lost.

How can packet loss occur?

Packet loss often occurs with a client-side networking issue; from being too far away from your wireless network to a faulty network cable -- even a solar flare passing through can interfere with the delivery of traffic.

What Is Packet Loss and why does it occur

However, that is not to say that packet loss always occurs due to a client issue! As mentioned above, it only happens to most users as a result of their own network, however, packet loss can occur anywhere throughout a packet's journey to a particular destination. Packet loss can occur due to any one (or more) of the following:

  • Interference
    • Poor wiring (damaged shielding on your Ethernet cable), high noise environments (example: your wiring around a microwave)
  • Congestion
    • This can be caused by a fibre cut (forcing traffic to be rerouted), DDoS attacks, overloaded routers, or overloaded ports (i.e. a way to think of this is with your home network; assuming you get the full speed of your 100 Mbps Internet package, your network will become "congested" when one user starts a download at full speed while another user attempting to watch a video will have little-to-no bandwidth left)

Conclusion

Having listed some of the most common ways that packet loss can occur, it becomes clear that it is very easy for a packet to be lost (once in a while). If packet loss occurs often to a specific network, it may be an issue of congestion; however, if packet loss only occurs on traffic exiting your network, it will likely be an issue with your wiring, choice of cabling or local congestion.

Glossary

DDoS

A Distributed Denial of Service attack is a category of attacks that target multiple areas on a server.

Packet Loss

Packet loss describes the percentage of packets that get lost during transit between a destination and source.

Ping

Ping is a tool used to measure latency, on the 3rd layer, to either a local or remote host.

Traceroute

Traceroute is a network diagnostic tool used for finding the path taken by a network packet to reach a destination IP.