KernWi-Fi builds carrier-grade Yaesu IMRS network

KernWi-Fi has delivered what it describes as Australia's first carrier-grade Yaesu IMRS network, linking multiple amateur radio repeater sites across the VK region over an IP backbone.

The rollout centres on Yaesu's Internet-linked Multi-Repeater System (IMRS), which connects digital voice repeaters via an IP network. KernWi-Fi built the backbone using techniques more commonly found in commercial telecommunications networks than in amateur radio deployments.

Amateur radio groups in Australia typically link repeaters using radio-frequency paths or basic internet connections, approaches that can limit redundancy and security. KernWi-Fi's design introduces higher levels of routing control, segmentation and failover.

The backbone uses OSPF for internal routing and BGP for external connectivity, with Ethernet-over-IP tunnels between repeater sites. Quality-of-service policies prioritise audio traffic across the network.

The design includes dual-ISP connectivity for failover. Each repeater site operates on isolated VLANs, with firewall rules restricting traffic, and uses industrial-grade routers and switches. Additional sites can be added without major redesign, positioning the deployment as a template for future repeater links and digital mode integration.

Volunteer-run repeater infrastructure often relies on mixed backhaul arrangements, creating inconsistencies across sites. KernWi-Fi applied stricter controls across the backbone, including VLAN segmentation to isolate repeater traffic, encryption and firewall policies to reduce unauthorised access, and centralised monitoring to limit on-site maintenance.

The project aligns with a broader shift in amateur radio toward internet-linked systems, including digital voice ecosystems such as WIRES-X that depend on IP connectivity for inter-regional coverage.

Clubs operating in remote or weather-exposed regions face higher maintenance demands and rely on predictable connectivity for organised nets and emergency communications.

Phil Kern, Director, KernWi-Fi, said, "This project demonstrates how enterprise networking principles can transform amateur radio infrastructure. By applying carrier-grade standards, we've created a system that is secure, resilient, and future-ready for the VK Australian community. Our approach integrates advanced routing protocols such as EoIP, OSPF, and BGP, ensuring dynamic failover and optimal traffic management across multiple repeater sites. We implemented VLAN segmentation and strict firewall policies to isolate voice traffic, which significantly enhances security and reliability. This design not only improves uptime but also simplifies remote monitoring and maintenance, reducing operational overhead. Most importantly, it provides a scalable foundation for future expansions, whether adding new repeaters or integrating emerging digital modes. It's a blueprint for how amateur radio can evolve using proven enterprise-grade technologies."

Operators in northern Australia highlighted the importance of reliability under harsh conditions.

Peter Clee, Repeater Program Co‐ordinator, Darwin Amateur Radio Club, said, "Up here, reliability isn't optional - it's the difference between a smooth net and silence during a weather event. The Kern-engineered network brings carrier-grade routing, clean separation of voice from public services, and centralised policy we can trust. For clubs in remote or cyclonic regions, that means clearer audio, faster recovery, and an onboarding process volunteers can follow step-by-step. It's a practical way to link into Australia's digital community while keeping maintenance simple and governance tight."

National net operators also emphasised consistency across long-distance links.

Chris Dimitrijevic, AUS REPEATER NET, South Pacific Contest Club President, said, "For national nets, predictability is everything. The Kern IMRS backbone provides consistent audio and deterministic paths across states, allowing net control to focus on running the program rather than firefighting. Clubs plug their DR-2X into the IMRS LAN, confirm peers, and they're immediately part of a wider digital community. It's a repeatable workflow that scales - from a single local link to a multi-state AUS REPEATER NET - without changing the operating discipline."

Volunteer groups noted simplified onboarding and integration.

Nathan Grundy, South Australian Repeater Group, said, "What impressed me most was how straightforward the onboarding is. The Kern Node arrives pre-configured, IMRS traffic is cleanly separated from public services, and the routing just works. For clubs, that means less time fighting configuration and more time running nets - and a clear path to scale as new sites come online. Also, in conjunction with Aust-Repeater Net 24160 SARG host a YSF to WIRES-X node (same room number 24160) which enables you to access the system from a Hotspot and/or an OpenSpot if you are away from a WIRES-X repeater or node; this is also linked into the new amazing sounding IMRS system."

KernWi-Fi expects additional repeater sites to join the IMRS backbone as clubs expand coverage and link more systems into national digital voice networks.