Case Study at EVN Macedonia

Last Updated on 2026-02-06

EVN Macedonia is a national electricity distribution and supply operator responsible for operating and maintaining critical metering and grid infrastructure across the country.

In this project, WM Systems acted as the technology provider, delivering an industrial communication solution specifically designed to meet the utility-grade reliability and cybersecurity expectations defined by EVN.

Background — The Existing Installation

EVN’s field meters communicate locally over RS485. For backhaul, sites already had a secure Ethernet/IP network. What was missing was a standardized, industrial gateway that could:

• Integrate legacy RS485 meters into the IP network
• Enforce strong, policy-compliant encryption
• Operate without relying on cellular connectivity
• Meet industrial reliability expectations inside cabinets and substations (contained multiple legacy devices with dense panel mounting and complex wiring arrangements typical for long-evolving utility installations)

Conventional IT routers did not satisfy the industrial interface and security requirements, while many metering modems provided only cellular connectivity, which was not suitable for an architecture based exclusively on LAN communication.

The Challenge That Triggered the Project

EVN required a device that simultaneously ensured the following:

• RS485 meter interface and Ethernet LAN uplink
• Strict IPsec / IKEv2 compliance (utility-grade cryptographic policies)
• DIN-rail, industrial form factor
• Long-term availability and stable operation
• No dependency on mobile networks (despite cellular hardware being present)

Furthermore, their cabinet installations were densely wired and space-constrained, making it difficult to integrate additional communication devices without increasing complexity and maintenance effort (limited space and complex wiring inside).

Their security specification was unusually detailed, mandating combinations of:

• AES-GCM and AES-CBC
• Multiple SHA hash variants
• Diffie-Hellman Group 14
• Pre-Shared Key (PSK) authentication

Why WM Systems was selected

WM Systems provided a purpose-built industrial router – the Industrial DIN Rail Router – that uniquely combined:

• Native RS485 + Ethernet in one DIN-rail device
• OpenWrt-based OS for transparent, auditable security configuration
• Proven high-security with IPsec / IKEv2 interoperability with strict policies
• Deep experience in utility and mission-critical deployments

Development Goals

• Secure IP-based remote meter access over LAN
• Full compliance with EVN’s IPsec/IKEv2 cryptographic policies
• Eliminate unnecessary cellular dependency
• Ensure stable long-term cabinet/substation operation
• Enable simple, space-efficient installation and clear wiring inside densely populated utility cabinets

The Implemented Solution

Industrial Ethernet DIN-rail Router featuring:

• OpenWrt operating system
• RS485 meter interface
• RJ45 Ethernet uplink
• IPsec tunnel with IKEv2 and PSK
• Transparent data forwarding (no protocol change on meter side)

Process flow

Meter → RS485 → WM Systems Industrial Router → IPsec Tunnel (LAN) → EVN Backend

Architecture 

Electricity Meter (RS485) →  Industrial DIN-Rail Router (with RS485, OpenWRT, IPSec, IKEv2 (PSK) → EVN Secure LAN / IP Network → EVN Backend Metering Systems

What the Router Solved

The device acts as a secure industrial gateway between legacy meters and EVN’s IP network, adding encryption and authentication at the network layer without touching meter protocols or requiring meter replacement.

This was crucial: security was added without altering the metering ecosystem.

Functional Benefits

• Encrypted communication over existing LAN infrastructure
• No reliance on mobile operators
• Seamless integration with legacy RS485 meters
• Centralized, standardized security enforcement
• Utility-grade hardware reliability

Measurable Outcomes

• Stable encrypted communication across all sites
• Zero data loss reported
• Full compliance with EVN security audits
• Successful rollout into operational grid environment

Business Justification that this approach allowed to EVN Macedonia

• Avoid costly meter replacement
• Avoid protocol or infrastructure redesign
• Align fully with internal cybersecurity standards
• Standardize meter communication securely across sites
• Confidentiality on connected devices: the Router interfaces with RS485 electricity meters selected by EVN. Specific brands and models are confidential per customer policy.

Lessons Learned

• Industrial routers can replace cellular modems in LAN-centric utility architectures
• OpenWrt platforms dramatically simplify compliance with complex security policies
• In utility procurement, cybersecurity requirements now outweigh connectivity requirements

Conclusion

This project demonstrates how a LAN-based industrial router can become a cybersecurity enforcement point in smart metering infrastructure — without cellular dependency, without meter replacement, and without protocol changes.

For utilities operating secure IP networks, this architecture provides a clean, scalable, and audit-friendly path to modernizing legacy meter communication.

Interested in similar projects?

Contact Sales to discuss your project and application.