AX.25 on Linux/Developing user-space tools: Difference between revisions

Revision as of 19:54, 2 May 2026

Note: This page is a work in progress. It is not yet complete, and it may contain inaccuracies or outdated information.

Main article: AX.25 on Linux

Following the removal of AX.25 from the Linux kernel, there is an opportunity for new user-space tools to fill the gap for various AX.25 use cases. Many of the building blocks already exist in open source.

Before starting a brand-new user-space AX.25 project, it might be worth looking first at software that already does some or all of the following:

Modem/TNC functions
AX.25 framing
KISS or AGWPE host-side interfaces
APRS, BBS, node, or messaging applications
Integration with modern Linux networking through user-space boundaries like TUN/TAP

Here are some open-source projects that might be worth inspecting. This is not an exhaustive list.

Project	Project page or repo	Technical scope	Why inspect it
LinBPQ, BPQ32	project page	AX.25 stack, node/BBS and APRS applications, KISS, multi-interface and IP integration	Reference for a broad all-in-one user-space packet-radio environment
JNOS 2	project page	AX.25 stack, node/BBS, APRS, and messaging applications, KISS, AXIP, AXUDP	Reference for structuring a nearly complete packet-radio stack in user space
Dire Wolf	GitHub	Modem/TNC functions, AX.25 framing, KISS, AGWPE, APRS tooling	Clear reference for a maintained user-space TNC and host-side interface layer
Xastir SoundModem	GitHub	Modem/TNC functions; serial KISS or Linux AX.25 integration	Reference for an older Linux soundmodem design that can operate either through serial KISS or kernel AX.25
QtSoundModem	project page	Modem/TNC functions, KISS, AGWPE	Another example of a user-space software-TNC design exposing standard host interfaces
tncattach	GitHub	KISS-based Linux network-device integration for IP and Ethernet-style networking	Reference for bridging a KISS TNC to a Linux network device without the old AX.25 kernel stack
Pat	GitHub	Messaging application, AX.25 support, AGWPE	Useful example of integrating AX.25 support into a modern end-user application
aprx	project page	APRS application, iGate and digipeater functions	Reference for a focused application that avoids general-purpose kernel AX.25 dependencies
YAAC	project page	APRS application and related tooling	Example of an application-layer design that works through external TNC interfaces

@@ Line 5: / Line 5: @@
 ''Main article: [[AX.25 on Linux]]''
-This section is primarily relevant to developers or those evaluating new work in the packet-radio ecosystem.
+Following the removal of AX.25 from the Linux kernel, there is an opportunity for new user-space tools to fill the gap for various AX.25 use cases. Many of the building blocks already exist in open source.
-AX.25 may be considered active enough to justify new user-space implementations. Many of the building blocks already exist in open source. Before starting a brand-new user-space AX.25 project, it might be worth looking first at software that already does some or all of the following:
+Before starting a brand-new user-space AX.25 project, it might be worth looking first at software that already does some or all of the following:
 * Modem/TNC functions
@@ Line 14: / Line 14: @@
 * APRS, BBS, node, or messaging applications
 * Integration with modern Linux networking through user-space boundaries like TUN/TAP
+Here are some open-source projects that might be worth inspecting. This is not an exhaustive list.
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