Why is it called packet loss?

Data usually travels over the internet in small sections of encapsulated data called packets. Packets contain information sent from the source address to the target device. Usually, such packets reliably reach their destination. However, when a packet gets lost in transit between two devices, it can never reach its destination. This is called a lost packet.

When a series of packets are lost in transit, it's called packet loss. Packet loss describes the percentage of packets lost between the sender and the destination.

How can you detect packet loss?

You might notice the term packet loss when using diagnostic tools like ping and traceroute. These diagnostic tools send a series of packets, usually over ICMP. The target device then responds by echoing back the response. We can measure the percentage of lost packets between the client and the destination by measuring the number of successfully communicated packets.

How can packet loss happen?

Packet loss often results from a client-side networking issue, such as being too far away from a wireless access point or using a faulty network cable. Even an untimely solar flare can interfere with the delivery of traffic.

What Is Packet Loss and why does it occur

That's not to say that packet loss always occurs due to a client issue. As mentioned above, packet loss often happens to users as a result of their local network connection. But packet loss can occur anywhere throughout a packet's journey.

Any of these factors can cause packet loss:

  • Interference: A signal disruption
    • Poor wiring, such as damaged shielding on an Ethernet cable.
    • High noise environments, such as wiring near a microwave
  • Congestion: A signal has to compete with other traffic
    • Fiber cuts can force traffic to be rerouted.
    • DDoS attacks
    • Overloaded ports and routers

Conclusion

Now that you know some of the most common ways that packet loss can happen, it's pretty clear that it's easy for a packet to get lost once in a while. If packet loss happens very often on a specific network, it might be an issue of congestion. If packet loss only occurs on traffic exiting your network, it's probably 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

The percentage of packets that get lost between a destination and a source.

Ping

A tool to measure latency on the 3rd layer.

Traceroute

A network diagnostic tool used to find the path taken by a network packet to reach a destination IP.