AX.25 For Linux 2.3

[features][release notes]
These pages do not deal with AX.25 and Linux in general, so don't expext to find answers for all day problems like "kissattach does not work" or "ax25rtd segfaults". What you will find here are informations about my new, completely rewritten AX.25 implementation for Linux 2.3.

But first, some answers:

Why at all?
When I started to run packet radio with linux, the only way to do TCP/IP over AX.25 was to use one of the NOS programs or Dieter Deykes WAMPES. What a bloated configuration! Two complete TCP/IP stacks with independent protocol implementations and services, both uneasy to configure and administer. Linux' own builtin support for AX.25 wasn't really usable at this time.

As time went on the builtin AX.25 evolved and I saw the chance to get rid of WAMPES. I compiled and installed the utils and found it almost usable, but with some really annoying flaws: it was painfully slow, it didn't allow digipeating across ports, the support for TCP/IP over "connected mode" AX.25 was rudimentary, and it had a hell lot of parameters that invited for misconfiguring them.

The first thing I hacked in was the TCP/IP header compressor and optimizer Gunter Jost (dk7wj) and I had developed to boost TCP/IP over Ax.25 virtual circuits. Doing this I got familiar with the structure of the code and linux' kernel internals in general and I found might be quite a fun to hack in the features I missed. But very soon I found that I'd better rewrite all of it instead of hacking the current code.

Why did you break all the drivers?
One task I wanted to accomplish was to have the kernel automatically figure out the optimum parameters for media access. The driver interface didn't allow this, so I changed it and broke the drivers. I fixed the drivers I need and those that seemed trivial and left the reminder broken to make people look up.

Why did some of the ax25-utils stop working?
Actually there is one class of utils that broke: Those that depend on the frame format of the packets delivered via the AF_PACKET capturing interface. The frame data was formerly prefixed by a KISS type identifier byte which is gone now. This applies to "listen", "ax25rtd" and the "ax25ipd", as far as I know. Other utilities shouldn't be affected. As soon as I find the time I'll provide patches for Craig Smalls wonderful new ax25-utils.

OK, that's it for now, folks, last question I answer is: "where do I get those patches?".

Theres more than one place to look for: You can directly download the latest patches from this site, just follow this link. If you have problems to access this site, have a look at There you'll not only find my patches but also recent versions of Craig Smalls ax25 utilities, among lots of other stuff.