Packet loss on the Internet: What’s its source and meaning?

M.Sc. Chris Wojzechowski

Packet loss on the Internet: What’s its source and meaning?

The Internet works a little differently than most people think. Especially on the technical side, there are things that need to be understood first in order to understand the big picture. Packet loss is one of those basics that, while often familiar in concept, is largely unknown in detail.

To change that, you should have heard about the foundations of the Internet before and also be able to understand terms like the TCP/IP protocol a little bit. We have published a short version of how the Internet works in this blog post.

Here we explain what packet loss on the Internet is all about, where the term actually comes from, what exactly packet loss is in the end, and how you can even protect yourself from it under certain circumstances. All as always with a strong focus on the safety aspects of the respective technology and function.

What is packet loss anyway?

When large amounts of data are sent over the Internet or the TCP/IP protocol, they must be split. This happens because many smaller packets are usually safer in transit than one large one. A small packet can be resent more quickly if lost than a large one.

Basically, large data is divided into many small packets that are sent and then reassembled at the recipient. If a considerable number of these packets are lost, problems arise when they have to be reassembled at the recipient’s premises. It’s kind of like ordering a couch, but then in the end the packet with the cushions is missing or the cushions arrive damaged. The couch is then there, but an important part is missing.

If packets are lost en route, this is referred to as packet loss. The longer the distance when sending, the more often packets are lost en route. In principle, this is not a problem as long as the number of lost packets is kept within reasonable limits. Even if the Internet connection is poor, such a packet loss may occur.

The packet loss is clearly visible in video or voice chats. If a packet loss occurs here, the picture jerks, errors occur or the voice stops and is only transmitted distorted. The greater the packet loss, the greater the connection problems.

How does packet loss occur?

There are many reasons for packet loss. Often it is simply due to a hardware defect at the responsible Internet Service Provider (ISP). If an important component or a router fails there, the corresponding customers subsequently lose packets.

The routers at the ISP basically tell the packets which path to take. You can think of it like a highway. If there is too much traffic there, there will be a traffic jam (slow Internet) and sometimes accidents (packet loss). In most cases, however, modern technology easily compensates for a small loss. So, in case of packet loss, there is only a traffic jam, not an accident.

Causes for packet loss are, as just mentioned in the example with the highway, an overload of the network infrastructure. Software-related errors can also be the cause, just like incorrect configurations or insufficient hardware. There are really many reasons for this, and it is usually impossible to completely avoid packet loss. Therefore, first and foremost, make sure that the causes do not lie with yourself.

What can be done about it?

As mentioned, not really much. If the software and hardware on your side are in order, it is up to the Internet Service Provider (ISP) and you have no special influence on that. You must therefore live with the packet loss and accept it or report the problem to the provider so that any defects can be identified quickly and then fixed promptly.

If it is a corporate network where packet loss occurs and you are responsible for the technology, you should test the hardware as soon as possible. In this case, however, we certainly don’t have to explain to you what packet loss is in the first place and what can be the reason for parcels being lost en route. You should then already know about it in the best possible way.

Anything running scans and systems on the network can cause the packet loss as well. So quit any virus scanners, malware programs, restart routers and check any configurations that have been added recently.

How to test for packet loss?

Fortunately, under Windows it is easily possible to track packet loss via various terminal commands. This even succeeds relatively easily and can be completed by laymen without further ado.

Since the terminal commands are done one after the other and there is already a good tutorial, we would like to link to a corresponding article on this at this point. Just scroll down a bit and follow the instructions in the “test packet loss” paragraph to do just that. Afterwards you will know more.

In your own network or the company’s network, you can manage packet loss through various systems for monitoring. With such tools, it is easy to detect packet loss early and possibly take appropriate countermeasures if the problem is really yours.

How big is the security risk?

Packet loss may well be a component of common cyberattacks. A DDoS attack involves, among other things, deliberately inducing congestion, which in turn leads to packet loss. As a result, it is impossible to still access the corresponding offer correctly because the respective packets are missing.

At the same time, packet loss means a potential security risk because manipulated packets could be sent. Interception is also theoretically possible. In security-relevant areas, the loss of a packet is therefore always a reason to question the security strategy and to check whether everything is still in order.

In conclusion, packet loss is simply part of the Internet. You have surely experienced that a conversation suddenly dropped out or the video chat showed faulty images and disturbed fragments. If there is a lot going on on the Internet, packet loss can rarely be avoided. Modern technology, however, ensures that we no longer even notice these little hiccups of the Internet. If it does, however, you should check whether it’s you or the network in question.

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M.Sc. Chris Wojzechowski

My name is Chris Wojzechowski and I studied my Master in Internet Security in Gelsenkirchen a few years ago. I am one of two managing directors of AWARE7 GmbH and a trained IT Risk Manager, IT-Grundschutz practitioner (TÜV) and possess the test procedure competence for § 8a BSIG. Our bread and butter business is performing penetration testing. We are also committed to promoting a broad understanding of IT security in Europe, which is why we offer the majority of our products free of charge.