What is Deep Packet Inspection (DPI)?

What is Deep Packet Inspection (DPI)?

In Star Trek, when a crew member would call to be “beamed up” or transported to and/or from their ship, they were first “dematerialized” (broken into small particles) then beamed to the new location where the particles were reassembled. A true SciFi gem.

While in 2021 we’re still awaiting this next-level transportation tech, the thinking behind it is pretty similar to how information is sent and received across a network of computers. For example, when you visit a website, the host server does not simply send the whole thing over in one piece. Instead, everything is broken down into small segments of data known as packets, which are passed through the network and reassembled on your computer. At the same time, the host is also receiving data packets from its users, containing information such as location, IP address, etc.

Deep Packet Inspection (DPI) is a method of monitoring and managing network traffic in real time as packets arrive at different checkpoints/firewalls. DPI analyzes the contents of arriving packets then automatically decides how to handle them based on predetermined rules set by the host organization. With the constant threat of hackers and other cyber attacks, many organizations rely on Deep Packet Inspections as a firewall to ensure the security of their network and the safety of their users.

How Does DPI Work?

When a user visits a website, packets of data pass through different checkpoints throughout the host network. With DPI in place, these incoming packets are inspected and checked against a predetermined set of rules typically preprogrammed by an organization’s systems administrator or internet service provider (ISP). The system can then automatically decide how to handle each incoming packet based on these rules, enabling an organization to prevent hidden threats and attacks.

Deep Packet Inspection vs. Conventional Packet Filtering: What’s the Difference?

The difference between a Deep Packet Inspection and Conventional Packet Filtering has to do with how much of the packets are being checked. Conventional Packet Filtering would only inspect information included within the packet’s header, containing data such as IP address and port number. However, just checking the packet header is a lot like just reading the outside of an envelope – it doesn’t tell you much about what’s actually inside the packet. This unfortunately made it easier for threats hidden within a packet to sneak through the firewall.

Due to the processing speeds of the past, Conventional Packet Filtering was an organization’s best bet for managing traffic without completely slowing down their network. Deep Packet Inspection takes advantage of today’s improved processing power in order to perform deeper inspections in real time, even with higher traffic volume. Rather than just taking a look at the packet header, DPI also analyzes the contents of each packet, including data and metadata from each device on the network. In other words, a DPI is like opening up the envelope to verify its contents are safe.

The Benefits of DPI

Deep Packet Inspections offer several important benefits when it comes to an organization’s network.

  1. DPI can improve network security. By analyzing packets beyond the header, DPIs are able to catch threats or attacks that may be hidden in the contents. This allows an organization to more readily identify and block malware, data leaks, and other security threats to it’s network and/or users.
  2. DPI provides additional options for managing network traffic. For example, rules can be programmed to look for specific types of data and identify high and low priority packets. DPI can be used to give preference to higher-priority packets and pass it through the network first.
  3. DPI works for outgoing traffic as well. This can help prevent data leaks and identify where your data is being sent.
  4. Predetermined rules guide how DPI handles packets in real time. All packet information, from the header to its contents, are checked and automatically handled based on the preprogrammed rules that your team puts in place. This way your system can automatically sort, filter, and prioritize each packet without slowing down the network.

By looking more closely at packet contents as they pass through network checkpoints, DPI protects both an organization and its users while ensuring a smooth and responsive experience.

The Limitations of DPI

In the tech world, everything has certain limitations. While extremely beneficial for network monitoring and security, there are some things to look out for when it comes to DPI.

  1. Not everyone is a fan of this level of transparency. Because DPI has access to detailed data, such as where and who information is traveling to and from, some privacy advocates and those against net neutrality may not be in favor of DPI.
  2. DPI can be exploited to facilitate the very attacks it works to prevent. Unfortunately, certain cyber attacks such as buffer overflow, DoS (denial-of-service), and malware can still occur by exploiting a network’s DPI.
  3. While highly efficient, DPI does make for a more complex system. It must be effectively integrated with existing security software and firewalls. DPI requires plenty of upfront work when programming rules for handling packets, and must be revised and updated constantly to ensure optimal functionality.
  4. Increased burden on firewall processors from DPI may lead to slower network speeds. In some cases where processing power may be limited, the additional power required for a Deep Packet Inspection may cause the network to slow down.

Despite these limitations, many organizations have embraced DPI because of the benefits it offers regarding network security and traffic monitoring.

How is DPI Used in Tech?

There are several different use cases when it comes to DPI, including:

  • Network Security Tool – DPI analyzes packet contents to identify potential threats and/or security attacks. This helps organizations to determine where certain threats may be coming from in order to effectively prevent or block them in the future.
  • Network Traffic Management – Network traffic can be controlled to set preference for packets marked as high priority. This means business critical data can be prioritized over packets/messages that are associated with casual browsing.
  • Prevent P2P Downloading – Outgoing packets can be managed based on their contents and recipient in order to help prevent any unwanted P2P downloading.
  • Managing a Network of Remote Computers – Using DPI, organizations can manage remote workers who may be connected via VPN. DPI helps to prevent any unintentional spreading of spyware or other viruses from a team member’s personal computer to the organization’s network. This also allows the organization to decide which applications or services can and can’t be accessed by each team member.
  • Integrate with Alerting/Notification Software – If a threat or attack is detected by DPI, any necessary team members can be automatically notified using tools such as PagerDuty to improve incident response.

Start Integrating DPI at Your Organization

Deep Packet Inspection offers a number of benefits when it comes to an organization’s network security and traffic. If you’d like to learn more about how to get started with integrating DPI at your organization, we’d love to speak with you about your options and different tools to optimize your DPI processes. Please give us a call  to discuss how we can help implement DPI at your company, or start a free trial—no credit card required.