From: Terry Dawson (mjykak.bmyp@kerailya.tunkki.fi)
Date: Wed Jan 09 2002 - 13:03:45 EET
terhi.victor@logonet.com Gilks wrote:
> I'm confused by the documentation so I thought I'd ask the questions here so
> that Jeff Tranter can wrap up the answers (assuming you good people have
> some) in the next update to the ax25 howto.
fair enough too. I'm working from memory here, I don't have the HOWTO document
in front of me, so forgive any mistakes.
> 1. axports entry
> 1.1 How come none of the examples have no window size (unless the window is
> extracted from the string axip somehow)
I'm a bit confused by the double-negative in your question, but I'm assuming
the 'no' is superfluous.. the window setting here has the same effect as for
any other Linux AX.25 port, there is no intuiting of the window from the name
of the interface. It may just been an oversight in the history of updates of
the document. It's possible that when I originally wrote the AXIP section the
axports file didn't have the window setting, and in a later retrofit I've
forgotten to update it there.
> 1.2 Is the callsign associated with the axip entry a source or destination
> callsign. Is that what the other end of the IP link will see as the
> originator or is it the AX25 callsign of the other end of the axip link.
> Maybe its just a placeholder. How is that callsign used by someone making an
> ax25 call within earshot of this node.
It serves the same purpose as the callsign on any Linux AX.25 device. It is the
address of that AX.25 port, ie it is the 'source' callsign and is what will the
AXIP peers will see for simple AX.25 connections.
> 2. ax25ipd.conf
> 2.1 Having said that the tnc and digipeater modes differ, how does the
> digipeat mode work.
In digipeater mode the ax25ipd program itself assumes a callsign and you, and
the AXIP peers, treat it like it is a digipeater.
In 'tnc' mode the ax25ipd looks like a TNC to the host computer and doesn't
have a callsign of it's own, just picks AX.25 frames up, encapsulates them and
sends them on their way.
> 2.2 Loglevel 2 would appear to contradict the statement that logging doesn't
> work (one line above it)
That's probably an artefact of the original ax25ipd.conf file that comes with
the native package. ax25ipd was originally developed many years ago, prior to
Linux even existing I think. It's been a bit of a work in progress for quite a
while. The example configuration file out to probably remove that confusion.
> 2.3 I'm using an 8 port TNC - does that mean I need 8 optional callsigns in
> the mycall section (since a dual port TNC requires 2 calls)
Um. no, I don't think so. I recall that the 'mycall' option is only used in
digipeater mode and sets the callsign that ax25ipd assumes as its own. I can't
see how ax25ipd when used as described cares how many ports your TNC has.
> 2.4 The broadcast section is commented out in all examples I've seen - does
> this mean it doesn't actually work?
broadcast section?
Do you mean:
broadcast QST-0 NODES-0
# Valid flags are:
# b - allow broadcasts to be transmitted via this route
# d - this route is the default route
route vk3wrm-0 203.13.168.95 b
route kb7pwd-0 24.1.227.2 b
It should work. It certainly works for me. I've no idea why it'd be commented
out in the HOWTO. I remember adding it in.
> 2.5 Having declared a pseudo tty, the speed is then set - what is the point
> in setting the speed of a non-existant physical device thats running at
> multi-megabits/sec?
There is no point, and the speed setting in the configuration will probably be
ignored. ax25ipd can be used on native Unix machines in such as a way that
rather than a pty, you use a real serial device and you can hang a KISS TNC off
that. ax25ipd will drive a KISS TNC when in digipeater mode. The speed setting
is relevant only in that configuration. Still, it's a required parameter I
think which is why I'd have included it in the configuration. I'm fairly
certain the actual value is inconsequential when it's talking to a pty.
> 3. user interface
> 3.1 How does a dumb user access an axip link - does he have to connect to
> the box and rummage through the ports list to find the axip entry and then
> make a call using that as the port?
ax25ipd looks just like any other Linux AX.25 device. Users use it precisely
the same way. Imagine the axip port being a real KISS TNC with a very limited
number of station reachable via it.
> 3.2 Is there a way of using a broadcast to notify local uses of what is
> available at the other end of the axip link (assuming they can use it
> directly somehow) - its not clear which direction the broadcast goes - down
> the hole or out locally.
no.
if you're talking about the 'broadcast' setting here, it's an outbound setting
only. All it really is a hack to allow AX.25 broadcast traffic, like NetRom
broadcasts, to be directed across *mlutiple* axip associations. As the ax25ipd
originally stood you could map a destination AX.25 address to only one
destination axip peer.
> Sorry to play the "devils advocate" on these questions but here in the UK we
> are starting to see a rise in the cost of Internet access which may bring a
> few people back to packet. I'd like to be ready for them (and their
> questions!!)
good luck.
regards
Terry
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