Packet Radio in 2026: Is AX.25 Still Relevant?

AX.25 turned 40-something years old and people keep writing its obituary. Every couple of years a thread pops up on r/amateurradio asking if packet is dead, and every time, the answers split right down the middle. Half the replies say it's ancient tech that needs to die. The other half point out they used it last Tuesday.

So which is it? Let's look at where AX.25 packet radio actually stands right now, what still depends on it, and whether there's any reason to set up a TNC in 2026.

What AX.25 Actually Is (Quick Refresher)

AX.25 is a data link layer protocol adapted from X.25 for amateur radio use. It handles framing, addressing (using callsigns instead of IP addresses), and error correction over RF links. The protocol was formalized in the early 1980s and became the backbone of amateur packet radio networks.

The basics: you key up on a VHF or HF frequency, transmit data frames at 1200 baud (VHF) or 300 baud (HF), and the receiving station acknowledges each frame. Connected mode gives you reliable delivery. Unconnected (UI frames) gives you broadcast capability.

That's it. No encryption, no fancy modulation, no adaptive rate control. Just frames on RF.

Where AX.25 Still Lives

Here's the thing. AX.25 isn't thriving, but it's far from dead. It underpins several systems that hams use every single day.

APRS

The Automatic Packet Reporting System runs entirely on AX.25 UI frames. Every APRS position beacon, weather report, and message you see on aprs.fi is an AX.25 packet at 1200 baud on 144.390 MHz (in North America). The network of digipeaters and IGates that make APRS work are all speaking AX.25.

APRS isn't going anywhere. It has a massive installed base, works without internet infrastructure, and does its job well enough that nobody's seriously proposing a replacement protocol for the RF side.

Winlink

Winlink's RF connections still use AX.25 as the transport on VHF/UHF (through VARA FM as well, but plenty of stations still offer AX.25 access). The HF side has largely moved to VARA HF, which offers dramatically better throughput, but AX.25 remains a fallback option.

BBS Systems and Nodes

Yes, packet BBSes still exist. No, they're not bustling. But in some regions (parts of Europe, Australia, and scattered US cities) there are still active BBS forwarding networks. I stumbled onto a functioning packet BBS network in the Pacific Northwest last year while testing a new TNC. Three active nodes forwarding traffic nightly. Not exactly a thriving metropolis, but it was running.

Emergency Communications

This is where AX.25 has real staying power. ARES and RACES groups in many counties still maintain packet infrastructure as a backup data path. During the 2023 Maui wildfires, packet nodes helped relay traffic when cell towers went down. It's slow, it's clunky, but it works when nothing else does.

The Problems With AX.25 in 2026

Look, I'm not going to pretend the protocol doesn't have serious limitations.

1200 baud is painful. On VHF, the standard data rate is 1200 bits per second. That was reasonable in 1983. Transferring even a short email takes noticeable time. Some stations run 9600 baud, but adoption is spotty and requires specific radio hardware (a data port with flat audio, not the mic/speaker jacks).

No modern error correction. AX.25 uses a simple checksum and retransmission scheme. Compare that to something like VARA, which uses adaptive modulation and forward error correction. On a noisy HF path, AX.25 at 300 baud will struggle while VARA pushes through.

The hardware situation is weird. Traditional TNCs (the Kantronics KPC-3+, the MFJ-1270 series) are out of production. You can still find them used, but new operators are more likely to use a software modem like Direwolf with a sound card interface. Direwolf works great, but it's another piece of complexity.

I spent a weekend last summer trying to get a Raspberry Pi running Direwolf to reliably connect to a local packet node. The audio levels, the PTT timing, the squelch tail issues. Took me four hours of tweaking before I got a solid connection. Not exactly plug-and-play.

No one's developing it. The AX.25 spec hasn't been meaningfully updated in decades. No new features, no performance improvements. The protocol is frozen in amber.

What's Replacing It (Or Trying To)

Several newer protocols aim to do what AX.25 does, but better:

• VARA (VHF and HF versions) — proprietary but widely adopted for Winlink. Dramatically faster than AX.25, with adaptive modulation up to 8490 bps on HF
• New Packet Radio (NPR) — a 70cm broadband data system running at 500 kbps using commercial FPGA modules. Completely different beast from traditional packet
• M17 — an open-source digital voice and data protocol. The data side could theoretically replace AX.25 for some applications
• Reticulum — an emerging network stack designed for unreliable links. Not AX.25-compatible but solves similar problems with modern cryptography

None of these have the install base of AX.25 yet. That's the catch.

Should You Bother Setting Up Packet in 2026?

Honestly? It depends on what you want out of it.

Yes, if:

• You want to run APRS (you'll be using AX.25 whether you think about it or not)
• Your local EmComm group uses packet
• You're interested in the history and want to experience it firsthand
• There's an active packet node or BBS in your area (check on packet-radio.net)

Probably not, if:

• You want fast data transfer over RF (look at VARA or NPR)
• You're hoping for an active chat community (those moved to JS8Call and Discord years ago)
• You don't enjoy troubleshooting legacy systems

I'll get some pushback for this, but here's my take: AX.25 is legacy infrastructure that still serves specific, valid purposes. It's not exciting. It's not growing. But calling it irrelevant ignores that APRS alone justifies its continued existence, and the EmComm applications are genuinely important.

Getting Started If You Want To Try

The cheapest way in:

1. A VHF radio with a 1200 baud packet-capable data port (or just use the speaker/mic jacks with level adjustment)
2. A USB sound card interface (Digirig, SignaLink, or homebrew)
3. Direwolf software modem running on a PC or Raspberry Pi
4. A packet client like Outpost PM or BPQ32

Total cost if you already have a 2m radio: maybe $50-80 for the interface. Direwolf is free.

Connect to your local APRS frequency and decode packets first. Just receive. See what's out there. Then try connecting to a local node if one exists.

The Bottom Line

AX.25 packet radio in 2026 is like a municipal water system built in the 1950s. Outdated engineering, nobody would design it that way today, but it still delivers water to thousands of homes and ripping it out would cost more than maintaining it.

The protocol will fade eventually. VARA and newer systems are technically superior in every measurable way. But "eventually" isn't this year, and probably isn't next year either. APRS keeps it alive, EmComm keeps it funded, and inertia keeps it running.

Not dead. Not thriving. Just... there. Doing its job.