Packet Loss

Packet loss causes reduced throughput, diminished security, and other issues in your network. Learn about causes and effects and how you can mitigate its impact.

What is Packet Loss?

Packet loss happens when a network flow has an incomplete delivery, with only partial packet data transmission. Messages that are missing packets arrive more slowly, are lower quality, and negatively impact the user experience.

What this looks like to a user is choppy conference calls, slow web page load times, and timed-out applications. When a packet is dropped, the internet’s Transmission Control Protocol (TCP) attempts to recover it, resending the message and further slowing the process.

With voice and video, this retransmission is not possible over live calls. It violates the deadline expiry, so rather than experiencing a delay while waiting for a recall of the missing packets, the call moves forward as is, with degraded quality. You might be familiar with the glitchy visuals and choppy sound, the robotic quality, and speed irregularities in speech on video platform calls. This is caused by packet loss.

How is Packet Loss Measured?

Packet loss is expressed as a percent and follows this formula:

Packet Loss % = (Packets Sent – Packets Received) / Packets Sent

The packet loss ratio is the number of lost packets to the total number of packets sent.

If you ping the host 100 times and only get 96 responses, you are experiencing a packet loss ratio of 4%.

What is Acceptable Packet Loss?

This depends on who you ask and how you are using the network traffic. Video packet loss becomes noticeable in the user experience at the level of .05% and becomes truly obnoxious at around 2%. With non-video VoIP calls, the 5% – 10% mark is when VoIP calls become significantly impaired.

Many industry voices claim that the only acceptable level of packet loss is 0. TCP/IP tolerates a packet loss anywhere below .1%. Ideally, you should target a packet loss ratio of less than .1%.

What are the Common Causes of Packet Loss?

We’ve narrowed the causes of packet loss down to four common areas.

Congested Routes

Packets wait in a first-in-first-out queue or are marked by priority using QoS as they are transmitted to their destination. If the queue becomes too crowded, the overtaxed device manages the demand on its routing capacity by using a buffer (which slows traffic) or dropping packets (which degrades traffic).

Network congestion leading to overburdened equipment is the main cause of packet loss. All networks have space limitations and, without adequate network capacity planning, will be unable to manage their experience peak-hour data transmission, resulting in packet loss.

Out-of-Date, Buggy Software

The software you use is critical to creating and sending data from point A to point B. If it is not updated, bugs can prevent it from performing optimally. It could also be hogging significant bandwidth because of issues addressed in more recent versions.

Keeping software updated helps ensure traffic performance without packet loss. Apply updates and reboot your hardware for the patches to take effect.

Network Hardware

End-of-life or outdated network hardware does not have the same throughput as modern, updated components. Routers, firewalls, bridges, hubs, and switches can all be the bottleneck in freely passing high-volume traffic.

Security Attacks

Sometimes packet loss is caused intentionally by malicious targeting of your network. This can be a denial-of-service attack (DoS) or a distributed denial-of-service attack (DDoS), which floods the network with traffic to force the system offline. DoS attacks can be stopped by blocking the IP address flooding the network; DDoS attacks are more difficult to control because of the alternating IP addresses contributing to the attack.

Attackers can also execute a packet loss attack where they take over your router and send a command that makes it drop packets. To resolve this, you will need to disable remote administration, update the firmware, and change the usernames and passwords associated with the router.

What are the Effects of Packet Loss?

The effects of packet loss can differ depending on the protocol used. TCP will attempt to resubmit the packet, but UPD (User Datagram Protocol) will not. This makes UPD generally faster but less reliable for packet throughput, our first effect caused by packet loss.

• Reduced throughput of a connection, resulting in reduced speeds across a network.
• Real-time application delays (voice or video)
• Security lapses can be caused by back door entry via dropped packets to VoIP applications.
• Higher latency for the transmission of data; data now must be resubmitted for the information from the lost packets to arrive.
• Operational costs from less effective systems and less productive employees

How to Prevent Packet Loss

Prevent packet loss by following these best practices. We’ve listed our tips in order of importance for maximum impact on your network.

• Reboot your system
  • Restarting your network devices will clear the cached memory and improve throughput.
• Update/upgrade your software
  • Outdated software can contain bugs that create abnormal network behavior, including packet loss. Update your software to the latest version and reboot your systems to make sure all the patches are applied
• Use wired connections instead of Wi-Fi
  • Switching to an ethernet connection has more stable results and can be a temporary fix for packet loss.
• Use Quality of Service (QoS)
  • Applying a critical eye to QoS keeps business-critical applications prioritized over other applications like email, where packet loss is less impactful.
• Complete routine network connection checks
  • Check cables and cords for loose connections.