Network TAP for Railway Signal Box Traffic Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing railway operating systems face challenges in protecting the interlocking from malicious network traffic via communication networks, which can compromise the safety of the railway operations.
Innovation Solution
A network TAP is used to read incoming network traffic and output it to a processor for checking, with a network separation device separating the interlocking from the communication network if impermissible commands are detected, ensuring the interlocking is disconnected and thus protected from potential attacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the interlocking is connected to the communication network to enable remote monitoring and control, then operational convenience is improved, but vulnerability to malicious network traffic and safety risks increases
Solution Approach 1:
A network TAP (Test Access Point) is introduced as an intermediary device between the communication network and the interlocking system. The TAP provides a physical connection point that allows monitoring of network traffic without being directly visible or accessible to external network participants, thereby enabling safe remote monitoring while blocking direct attack paths to the interlocking.
Solution Approach 2:
The system is segmented into distinct functional zones: the communication network, the monitoring interface (TAP), and the protected interlocking system. This segmentation creates isolation layers that allow operational connectivity while preventing malicious traffic from reaching the safety-critical interlocking components.
2Reliability
If network traffic is monitored in real-time to detect unauthorized commands, then safety is improved, but processing time and system complexity increase
Solution Approach 1:
The monitoring function is extracted from the interlocking system itself and placed in a separate, dedicated monitoring interface (network TAP). This extraction allows the interlocking to focus on its primary safety functions while the monitoring system independently analyzes network traffic for unauthorized commands, reducing overall system complexity while maintaining high reliability.
Solution Approach 2:
The network TAP creates a passive copy of network traffic for monitoring purposes without intercepting or modifying the actual communication between the network and interlocking. This copying approach enables comprehensive security monitoring while keeping the primary communication path simple and efficient.
3Reliability
If the interlocking is separated from the communication network to prevent attacks, then safety is improved, but operational flexibility and remote access capability deteriorate
Solution Approach 1:
The network TAP serves as a controlled intermediary that maintains the interlocking's separation from direct network access while enabling necessary remote operations. By providing a monitored interface point, the TAP allows legitimate remote access requests to be processed while blocking unauthorized or malicious traffic, thus preserving both safety and operational flexibility.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a device for monitoring network traffic coming into a signal box of a railway operating system via a communication network, comprising: a network TAP for reading the network traffic coming into the signal box via the communication network and outputting the read incoming network traffic to a processor in order to check the read incoming network traffic, and a network separating device for separating the signal box from the communication network, wherein the processor is designed to actuate the network separating device on the basis of the result of the check of the read incoming network traffic such that the network separating device separates the signal box from the communication network. The invention additionally relates to a corresponding method and to a computer program.