EULYNX
EULYNX is a European railway initiative that standardizes the interfaces (SCI-P, SCI-LS, SCI-LX and others) between interlockings and field elements such as points, signals and level crossings. It replaces proprietary, relay-based connections with IP-based protocols, using RaSTA for safe transport.
How it works
EULYNX defines a set of Standard Communication Interfaces (SCI): SCI-P for points, SCI-LS for light signals, SCI-LX for level crossings, SCI-TDS for train detection and others, plus supporting protocols for maintenance (SMI) and diagnostics (SDI). Each interface specifies the messages exchanged between the interlocking and an object controller.
Messages travel over IP using the RaSTA protocol (Rail Safe Transport Application), which adds sequence numbers, timing checks and integrity codes to provide safe communication over standard networks.
Why it matters for security
EULYNX moves the interlocking-to-field link onto IP networks, enabling multi-vendor interoperability but also creating an addressable network where relays once sat. Its standardized messages are well suited to deep protocol inspection, making EULYNX deployments both a new attack surface and a monitorable one.
Related solution
Protecting interlocking systems at the core of rail safety
Deep inspection of standardized interlocking-to-field communications over IP.
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