Cover Story
Building a More Connected Amateur Radio Network
Hams Over IP is evolving from individual PBXs toward an interoperable communications ecosystem.
By WH6AV — Gescio “Jesse” Alpuro
Hams Over IP began with a simple idea: give licensed amateur radio operators another way to communicate, experiment and learn using familiar VoIP technology. As the network grows, the challenge is no longer simply adding another extension. The bigger question is how independent systems, regions and communities can work together while remaining manageable.
That is where much of our recent development has been focused: federation, distributed destination discovery, real-time presence, better self-service tools and stronger interoperability.
Regional PBXsOperators and services distributed across multiple systems
↔ Federation ↔Routing and discovery between cooperating networks
One CommunityMaking destinations easier to reach without hiding the technology
More than a single PBX
A multi-region network gives us opportunities that a single server cannot. Services can be placed closer to operators, systems can have distinct responsibilities, and experimentation can happen without requiring every feature to live in one place.
It also creates an engineering problem: how does one system know where a destination lives? Static routes work, but become harder to maintain as the number of systems and destinations grows. This is why technologies such as Asterisk DUNDi, along with carefully designed SIP and IAX2 interconnects, remain important parts of our work.
Interoperability is the goal
The objective is not to turn every amateur-radio VoIP system into the same network. Federation is useful precisely because independently operated systems can cooperate. A caller should have a clear way to reach a supported destination while each participating system retains control of its own users, numbering and infrastructure.
That philosophy also extends to endpoints. Hams Over IP should remain useful whether an operator prefers a desk phone, Wi-Fi handset, ATA, softphone, PBX or an RF-linked application.
Federation
Hams Over IP ↔ Amateur Wire
A new inter-network path demonstrates how independent amateur-radio VoIP communities can cooperate.
By Hams Over IP Editorial
One of the newest examples of interoperability work is federation between Hams Over IP and Amateur Wire.
The two networks remain independently operated, but defined dialing prefixes provide a path between them. From Hams Over IP, the 910 prefix is used when dialing toward Amateur Wire. In the opposite direction, Amateur Wire uses the 304 prefix when dialing toward Hams Over IP.
Why federation matters
Federation lets communities cooperate without requiring every user to move to the same PBX or numbering plan. It also gives us a practical environment for improving routing, monitoring and presence across network boundaries.
Behind a simple dialed prefix are several technical layers: route selection, inter-PBX signaling, destination validation and operational monitoring. Our goal is to make those layers reliable while keeping the operator experience straightforward.
Technical Corner
DUNDi: Discovery Before the Call
Distributed discovery can help Asterisk systems locate destinations without turning every route into a static configuration entry.
By Hams Over IP Editorial
Issue No. 3 previewed a closer look at DUNDi — the Distributed Universal Number Discovery protocol. DUNDi is not itself the voice trunk carrying a conversation. Instead, it can help participating Asterisk systems discover where a destination should be routed.
Think of the distinction this way: an interconnect such as SIP or IAX2 can provide the road between systems; DUNDi can help answer the question, “Which road should I use to reach this destination?”
Why discovery becomes important
With only two PBXs, maintaining routes manually is manageable. As more regions and cooperating systems appear, static routing tables can become repetitive and fragile. Distributed discovery provides another architectural option for locating destinations without forcing every PBX to maintain the complete network directory by hand.
We are continuing to evaluate where DUNDi fits alongside direct interconnects, local AstDB mappings and other routing mechanisms. The design priority is predictable calling behavior: local destinations should remain local, while remote discovery should happen in a controlled order.
Premium Update
More Control for Premium Operators
Mail, call forwarding, voicemail improvements and broader device compatibility expand the Premium experience.
By Hams Over IP Editorial
Hams Over IP Premium continues to add tools that give operators more control over their own communications.
- Premium Mail: internal messaging using addresses based on an extension or callsign, such as
400000@PREMIUM or WH6AV@PREMIUM. - Call forwarding: operators can enable forwarding with *72 and disable it with *73.
- Voicemail and MWI: ongoing work is improving mailbox synchronization and message-waiting indication behavior.
- Device compatibility: provisioning rules can accommodate equipment that imposes shorter SIP-password limits, including certain Polycom and Avaya devices.
- Support workflow: continued improvements are bringing ticket activity and administrative notifications closer together.
The common theme is self-service. Routine account tasks should be easy for operators to perform without hiding the underlying VoIP concepts that make the system useful as a learning platform.
Live Phonebook
Presence That Actually Looks Alive
Event-driven BLF and locally hosted map resources are making the phonebook faster and more dependable.
By Hams Over IP Editorial
A phonebook becomes much more useful when it can tell you what is happening now. Recent work on Hams Over IP and Amateur Wire phonebook services has focused on event-driven presence rather than repeatedly refreshing an entire page.
Depending on the resource, the interface can represent states such as AVAILABLE, BUSY, RINGING, HOLD and UNAVAILABLE. The important part is accuracy: an offline endpoint should not be painted green simply because it exists in a database.
Push instead of poll
Asterisk Manager Interface events can be consumed by the phonebook service and pushed to connected browsers. This reduces unnecessary refreshes and lets state changes appear much closer to real time.
The Hams Over IP phonebook map has also moved toward locally hosted map resources, reducing dependence on a public tile service for a core part of the interface.
Endpoint Workshop
Why Does My SIP Phone Show UNAVAILABLE?
Registration expiry, NAT, Wi-Fi and keep-alive behavior can all affect endpoint reachability.
By Hams Over IP Editorial
One of the most confusing endpoint problems is a phone that was working normally and later appears UNAVAILABLE. In many cases, the PBX no longer has a current reachable contact for that extension.
SIP registrations expire. Phones therefore refresh their registrations periodically, and many devices can also use SIP OPTIONS keep-alives to help maintain and verify reachability. Wi-Fi roaming, NAT mappings, router behavior, power-saving features and network interruptions can all affect that process.
A useful troubleshooting order
- Check whether the phone itself still reports the account as registered.
- Confirm that the device still has working network connectivity.
- Verify the configured registration server, port and transport.
- Review registration expiration, retry and keep-alive settings.
- If the problem is intermittent, note whether it follows Wi-Fi roaming, sleep/power saving or a particular network.
Do not treat an UNAVAILABLE state as a reason to change every SIP setting. First determine whether registration disappeared, whether the contact is stale, or whether signaling can no longer reach the device.
Did You Know?
Dial a Callsign, Not Just an Extension
Callsign dialing adds an amateur-radio-friendly directory layer to multi-region VoIP routing.
By Hams Over IP Editorial
Extensions are precise, but amateur radio operators naturally remember callsigns. Hams Over IP callsign dialing is designed to translate a callsign into the appropriate destination and then place the call through the correct routing path.
In a multi-region environment, lookup order matters. A local Premium mapping should be considered before sending a lookup toward another region. This keeps local calls local and avoids a remote result unexpectedly overriding the intended destination.
Callsign dialing is a good example of the experience we want to create: simple at the telephone, but backed by deliberate routing logic that remains understandable to operators and administrators.
Community Update
A Valid Amateur Radio License Is What You Need
DMR identification is not a requirement for obtaining Hams Over IP service.
By Hams Over IP Editorial
A reminder for new applicants and staff: a valid amateur radio license is the requirement for Hams Over IP service. A DMR ID is not required.
Where available, supporting directory information can be retrieved automatically rather than turning it into another hurdle for the applicant. The goal is to verify eligibility while keeping signup straightforward.
From the Founder
Interoperability Without Losing the Experiment
The network grows when independent systems and operators can work together.
By WH6AV — Gescio “Jesse” Alpuro
Every new feature is useful, but the larger objective matters more: Hams Over IP should be a place where amateur radio operators can communicate, experiment and learn how modern IP communications actually work.
Interconnection is a natural part of that. We do not need every system to be identical. We need well-defined ways for independently operated systems to cooperate, dependable tools for the people maintaining them, and an operator experience that encourages experimentation rather than getting in the way of it.
Thank you to everyone testing endpoints, reporting problems, connecting systems, answering questions and helping other operators get on the air—or, in this case, over IP.
73,
WH6AV — Jesse
Founder, Hams Over IP
Next Issue
Coming in Issue No. 5: Real-Time State
From Asterisk events to BLF lamps and live dashboards.
By Hams Over IP Editorial
For Issue No. 5, we plan to go deeper into the operational side of the network: BLF, AMI events and real-time state.
We will follow an endpoint from registration through device state and presence, explain how Asterisk exposes that information, and look at how dashboards and phonebooks turn raw events into useful operator information.
