Over the past few years, digital services have grown rapidly in both scale and complexity. Alongside that growth, DDoS attacks have evolved from simple traffic overload into forms that target the behavior of the application itself.
This shift makes it clear that traditional network-layer (L3/L4) defense alone is no longer enough.
The Structural Limits of L3/L4-Centric DDoS Defense
Most existing DDoS protection solutions have relied on detecting and blocking abnormal traffic at the IP, port, and protocol level. This approach has clear strengths:
- Relatively efficient response to high-volume UDP/TCP flooding
- Fast filtering of attack traffic
- Simple policy enforcement at the infrastructure level
But as attack techniques grow more sophisticated, problems emerge that L3/L4-based defense alone cannot solve.
- Difficulty distinguishing attacks that mimic legitimate traffic patterns
- Vulnerability to attacks that abuse application protocols
- Rate-limit-based responses risk blocking legitimate users at the same time
- Stateless filtering cannot make precise judgments through session tracking
As a result, an attack may be mitigated while service quality degrades along with it.
Attacks That Target the Application, Not Bandwidth
L7 attacks don't simply send large volumes of traffic — they overload the work the application actually has to perform.
Examples:
- Sending large volumes of HTTP authentication and search requests
- Exploiting the TLS handshake to exhaust CPU resources
- Spoofing game protocols (e.g., Minecraft, FiveM, RakNet) to occupy server threads
- Repeating incomplete session requests against real-time services such as VPN and SIP
These attacks can bring down an entire service even without large traffic volumes. In other words, detection is only possible by understanding protocol behavior — not through simple packet filtering.
PacketStream's Approach: Stateful + Payload-Based L7 Protection
PacketStream designed its L7 defense around two core principles.
Stateful Session Tracking
Every connection is tracked at the session level, and legitimacy is judged based on the temporal patterns and state changes of the traffic. This makes it possible to quickly detect spoofing-based attacks and incomplete session requests.
This stands in contrast to the many existing solutions that rely on stateless, rate-limit-based policies.
Payload-Level Validation
Depending on each application's characteristics, packet payloads are inspected directly to perform authentication and validation at the protocol level.
This approach detects forged application requests, minimizes the impact on legitimate users, and enables protection specialized for each protocol.
In short, attacks are identified by "what is being requested" — not merely by packet volume.
Supported L7 Protocols
PacketStream's L7 protection model is designed to support not only general-purpose HTTP/TLS but also a range of real-time protocols across gaming, communications, and VPN.
Supported examples:
- HTTP / HTTPS
- TLS
- Minecraft
- FiveM
- SAMP
- ARK
- RakNet
- SIP
- OpenVPN
- Source Engine
It works by understanding and validating the payload structure specific to each protocol.
Toward a New Security Model
Modern DDoS attacks are no longer simple traffic-based attacks. Because attacks that abuse the protocols themselves are on the rise, protection must extend to the L7 layer as well.
PacketStream's solution builds on L3/L4 protection while extending the defense model to L7, delivering:
- Response to advanced application-level attacks
- Precise blocking with no loss of legitimate traffic
- Applicability across diverse service environments
- Stronger application-level stability
Ultimately, in modern service operations, L7 protection is becoming a necessity rather than an option.