We have likely all shipped a package at least once before. After addressing a parcel, it goes to the shipping center, where it will be sent off like a checkpoint. A shipping service usually needs only the destination address to deliver a package, so it moves on as long as that information is present. But sometimes, workers may x-ray your shipment before sending it to the end destination. This process is similar to how deep packet inspection (DPI) works as data travels from your network across the internet. Keep reading to learn more.
What is a network data packet?
Your data doesn’t flow like water in a stream through the internet, and that’s good. A network packet allows information to be assigned and tracked in divided subsets. This way things are more organized and problems can be pinpointed more accurately. Any information sent or received online will be given to an encapsulated network packet with information about its origin and destination. Each network packet has three main parts:
The header contains basic summarizing information about the package and source/destination information. This includes IP addresses, the protocol in use, and the packet’s size (in bytes).
The payload is what’s inside the packet; the data being transmitted. This can be any data type, including text, media, etc. It all depends on the action being taken.
The trailer is a section of the network packet that checks the information for errors. This way, bandwidth isn’t spent on corrupted packets, and packets are sent in the correct order.
Simply put, the header and trailer of a network packet are designed to move the payload more efficiently through the network. The header gives basic information about the packet, and the trailer ensures the packet is readable and sequential.
The two types of packet inspections
Depending on the circ*mstance and the protocol, one of two types of packet inspection may be used to get your data from point A to point B. Although we are focusing on deep packet inspection, it’s crucial to understand the full scope of how your data moves throughout a network.
Conventional packet filtering is only used to check the header of a network packet. As previously mentioned, the header contains all the information necessary to move data along. It is simple and less-resource intensive which can improve the speed of your network overall.
Deep packet inspection (DPI) is used to check the entire contents of a network packet, including the payload. Sometimes a network is instructed to look at each packet closer before sending it to the receiver. It requires more resources to carry out and can slow down your network speed, but it has many trade-offs that could make it worth it.
How does deep packet inspection work?
Deep packet inspection is a robust system of checking packets, so many specific steps are involved. There is no exact process, and it varies depending on what tool you are using, but the basic breakdown is as follows:
- An incoming packet arrives at a network checkpoint (firewall, router, etc.) and is captured by the DPI tool.
- The DPI tool reads the header of the packet to assess basic information.
- This is the differentiating stage. The DPI tool reads the data packet’s payload and searches for pre-established patterns to determine the final steps.
- The DPI tool identifies the protocol used by the packet, which determines a set of rules the packet must adhere to to pass through.
- If the packet follows the rules, it can proceed to its destination.
- If a packet doesn’t follow the rules or has something else wrong, it will be blocked, flagged, or rerouted.
- Finally, the DPI tool will keep a log of packets that have been inspected and what happened to them. This is helpful for manual overview to reveal trends and keep records.
Why use deep packet inspection?
Let’s revisit our analogy from the intro. When a package is being sent to you, you may want to have it x-rayed. Especially if it comes from an unfamiliar source, it may be better to have a package fully inspected before opening it in your home. However, when sending a package, it would be an invasion of privacy for a mail worker (an intermediary between sender and receiver) to x-ray your package simply because they are curious about what is inside. We’ll go through all the ways to employ deep packet inspection when you want it and block it from happening when you don’t.
How to use deep packet inspection to your advantage
Fortunately, there are many ways that you or your business can use DPI to keep things running smoothly. Firstly, it can be used as an intrusion detection/prevention system to identify nefarious traffic such as malware, viruses, DoS, etc. In some cases, it can be even more resilient than an antivirus because it detects threats much earlier. However, it only works to prevent known threats and won’t be able to recognize new patterns. Either that, or you’ll have to set stringent policies that can hinder the performance of your network overall. In this case, you may benefit more from an antivirus. Similarly, DPI can prevent data loss by requiring employees to access certain information properly, keeping non-employees and eavesdroppers out.
See also: The 6 types of hacks you should know about
DPI can help your organization be organized by allowing you to direct traffic flow granularly. As the end-user, you can set your network up to prioritize certain types of traffic over others. This way, things run more smoothly as it would be custom-tailored to your workflow. While DPI can slow down your network overall, customization is one of the most significant advantages of using DPI. You can de-prioritize less important traffic to take the brunt of this slowdown.
How deep packet inspection can be used against you:
DPI can be invasive when used in an inappropriate context, and it is used by governments and internet service providers (ISPs) constantly. In countries that have restricted internet access, governments can use DPI to control the entire country. Often this includes censoring religious and political information based on discrimination, which can put citizens at risk of overreaching influence. As for your ISP, they can monitor your traffic to employ techniques like “bandwidth throttling”. This artificially slows down your network while streaming, gaming, etc. Not only that but they are even known to sell this data to advertisers to increase targeted advertising on your end in an attempt to sway your purchasing decisions.
See also: The easiest way to unblock YouTube videos
The best way to prevent unwanted DPI is by using a VPN. A VPN encrypts your network traffic so that it can’t be readily unpackaged and viewed by any third parties. Many companies are aware of the usage of VPNs and are using DPIs even more to combat that, which would put you at increasingly higher risk without some level of extra security. IPVanish offers over 2,200+ remote servers to choose from across 75+ locations, giving you many options to hide your IP address and browse freely without intrusion from your ISP or government.
See also: Why VPN? Prevent Deep Packet Inspection
