Hi Michael

If you just want to test the TX operation trying pinging a host in the
same subnet as to what you setup.

I do not understand why I would need to assign an IP address. I have done so
nevertheless, and it's pingable.

Well, When AX25 came out under Linux and even the NOS/KA9Q
implementations is was really meant to allow TCP/IP over packet radio.
In its heyday in Australia maybe 10 years ago you could do FTP, SMTP
mail transfers and so on. Our local gateway (tunnel to internet) also
picked up the NOS newsgroup and allowed users to POP3 get the articles
and so on. (This is the protocol most people use nowadays to receive
internet email)

It is really only of use to you if other amateurs in your area are
running TCP/IP on packet. I am actually playing with the userspace
soundmodem driver under Linux. It allows all types of different
modulation methods including the Q15X25 2500bps HF/SSB one. It just
comes up as another port/interface under Linux. Handy when the amateur I
am experimenting with doesnt have a telephone/modem!

----

Like I said, the latest ax25-apps and ax25-tools tarballs did not compile. I
found rpms specifically made for RH6.2 and installed them. After lots of
fiddling with the configuration, I tried "call bcsf0 callsign" just to
get an error message:
call: invalid port setting

I never had a huge problem but make sure that you also build libax25 as
well. Lots of its subroutines are used by "tools" and "apps". There is a
good chance that either the libax25 that is in the RH distro is out of
date or doesnt include the .h headers needed to compile apps and tools.

I am personally very wary of source RPM's and more often build direct
from tar.gz source.

Well you answered the call problem lower down with your axports comment
and the "call 1 callsign" grin

None of the available documents described how and where to assign a port
designator. I can tell you, after 6 hrs of trying in vain I was so mad and
ready to throw out the PC and modem and forget about PR once and for all.
Fortunately I didn't. This morning I found that I had to use "call 1
callsign", the "1" being the port number from /etc/axports. All of the
docs I read are describing this wrong.

Yes I found the AX25-HOWTO pretty limited as well. I can however see
where the port number (1 in your case is assigned) in my old KISS setup.
There is a command "kissparam" thats sets up the relationship between
the linux interface and the portname in /etc/axports. In my later
soundmodem setup both the linux interface and axports "port" has the
same name. I had thought that "sethdlc" also setup this relationship but
havent checked.

-----

Just one brief example: the AX25-HowTo talks about "insmod"ing modules

You should be able to get around this by the correct setup in
/etc/modules.conf. insmod is really only used for manual loading of
modules where the dependencies havent been defined in modules.conf. In
short when you try to run an AX25 app all the right modules should load
in the correct order. Most distros that have AX25 in the kernel already
have this setup. I have only needed to use module commands when I
totally wrecked modules.conf!

I should mention that if you want to use the kernel soundmodem driver
(as distinct from the userspace soundmodem driver) you will need to do a
bit of module fiddling. One has to remove the ordinary soundcard drivers
(ie to play music) to use it for packet. From memory this driver is also
not unloadable so to get your ordinary sound back a cold boot is needed.

BTW Linpac has the hooks to receive broadcast mail direct from your
local BBS. Give me a shout if you want to set that up as there is
another package you need.

I may come back for this when I feel comfortable with my setup.

I actually stopped using mine as the articles were mainly a lot of
recycled you know what. My packet use nowadays is pretty well restricted
to file tranfers direct from me to another amatuer.

Cheers Bob VK2YQA

Bob Bob wrote:

[snipped]

I seem to have the software tamed so that PR basically works, but I get
very low and flaky connection quality - tons of RR-/RR+ packets, but few
"payload" packets. I think I remember from my earlier packet days that
these are reject/acknowledge packets, indicating some sort of
misunderstanding between my station and the digi. Next thing I will
check at the weekend is the modulation deviation of my Kenwood transceiver.
Other than that, is there a document describing the ax25 parameters (Tn,
N2, idle, window) and useful values? Again the Ax25-HowTo is very
unprecise about those.

TIA,
Michael

Hi Michael

Will be off newsgroups for about a month from tomorrow..

As I recall packet neds a very good signal to noise. I have found that
even a S3 copy on 2m FM will be noisy enough for retries. If your RIT
works on FM check if you are on the digis exact freq.

The original NOS docs (wherever they may be) had discussions on these
parameters I think.

Shortening the max packet length gives better results in flakey
conditions because there is less time for the packet to be corrupted in.
Ensuring that the TXDelay and TXtail is both long enough and short
enough is also important. I remember setting my TXD by changing the
number dynamically as a ping job was in progress, then adding about 10%
when errors occurred. My old IC2A use to run at around 30mS but an older
relay based XTAL clunker needed 400mS. If you think it maybe a problem
(and remember that the time also helpds the other guys squelch open) set
it to something ridiculous like 1 second and see if the throughput improves.

The other timers (and persist/slottime) are more of use in crowded
channels so initially it probably isnt worth fiddling with. As a general
rule of thumb you would use what the local group are using so you had a
fair chance as them. Biggest problem is to ensure that you can hear
every other TX on your channel and they can hear you. Not a good idea to
use a yagi and low power because your (and their) collision rate will
skyrocket, despite any settings you use.

I'd accept the default settings as they appear in the proc filesystem,
set TXD and TXT by experiment, use the persist/slot that the local group
uses (or leave it as default), MaxFrame/window at 1 and thats it. If you
specifically want to use point to point with another station, make
persist/slot more agressive, fine tune the TXD, Maxframe/window to 7 and
make the packet length as long as possible.

I thought the howto actually described the params well enough for me..

Cheers Bob VK2YQA


Michael Hofmann wrote:
Bob Bob wrote:

[snipped]


I seem to have the software tamed so that PR basically works, but I get
very low and flaky connection quality - tons of RR-/RR+ packets, but few
"payload" packets. I think I remember from my earlier packet days that
these are reject/acknowledge packets, indicating some sort of
misunderstanding between my station and the digi. Next thing I will
check at the weekend is the modulation deviation of my Kenwood transceiver.
Other than that, is there a document describing the ax25 parameters (Tn,
N2, idle, window) and useful values? Again the Ax25-HowTo is very
unprecise about those.

TIA,
Michael

Hi Michael

Will be off newsgroups for about a month from tomorrow..

As I recall packet neds a very good signal to noise. I have found that
even a S3 copy on 2m FM will be noisy enough for retries. If your RIT
works on FM check if you are on the digis exact freq.

The original NOS docs (wherever they may be) had discussions on these
parameters I think.

Shortening the max packet length gives better results in flakey
conditions because there is less time for the packet to be corrupted in.
Ensuring that the TXDelay and TXtail is both long enough and short
enough is also important. I remember setting my TXD by changing the
number dynamically as a ping job was in progress, then adding about 10%
when errors occurred. My old IC2A use to run at around 30mS but an older
relay based XTAL clunker needed 400mS. If you think it maybe a problem
(and remember that the time also helpds the other guys squelch open) set
it to something ridiculous like 1 second and see if the throughput improves.

The other timers (and persist/slottime) are more of use in crowded
channels so initially it probably isnt worth fiddling with. As a general
rule of thumb you would use what the local group are using so you had a
fair chance as them. Biggest problem is to ensure that you can hear
every other TX on your channel and they can hear you. Not a good idea to
use a yagi and low power because your (and their) collision rate will
skyrocket, despite any settings you use.

I'd accept the default settings as they appear in the proc filesystem,
set TXD and TXT by experiment, use the persist/slot that the local group
uses (or leave it as default), MaxFrame/window at 1 and thats it. If you
specifically want to use point to point with another station, make
persist/slot more agressive, fine tune the TXD, Maxframe/window to 7 and
make the packet length as long as possible.

I thought the howto actually described the params well enough for me..

Cheers Bob VK2YQA


Michael Hofmann wrote:
Bob Bob wrote:

[snipped]


I seem to have the software tamed so that PR basically works, but I get
very low and flaky connection quality - tons of RR-/RR+ packets, but few
"payload" packets. I think I remember from my earlier packet days that
these are reject/acknowledge packets, indicating some sort of
misunderstanding between my station and the digi. Next thing I will
check at the weekend is the modulation deviation of my Kenwood transceiver.
Other than that, is there a document describing the ax25 parameters (Tn,
N2, idle, window) and useful values? Again the Ax25-HowTo is very
unprecise about those.

TIA,
Michael

Bob Bob wrote:

[snipped]

I seem to have the software tamed so that PR basically works, but I get
very low and flaky connection quality - tons of RR-/RR+ packets, but few
"payload" packets. I think I remember from my earlier packet days that
these are reject/acknowledge packets, indicating some sort of
misunderstanding between my station and the digi. Next thing I will
check at the weekend is the modulation deviation of my Kenwood transceiver.
Other than that, is there a document describing the ax25 parameters (Tn,
N2, idle, window) and useful values? Again the Ax25-HowTo is very
unprecise about those.

TIA,
Michael