[xfbb] AX25-->FBB failure

[Bo Skoglund]

Hi Barry.

The problem might be in fbb and/or in the basic ax25 setup and/or in the radio/tnc-matching.

The steps to solv the problem:
1. Is the basic ax25 setup ok?
2. Is the KISS really on?
3. Is the TNC matched to the radio according to signal levels?
4. Is fbb setup ok?

Step 1: Check the ax25 setup.
/etc/ax25/axports
/etc/ax25/ax25d.conf
kissattach of the TNC is ok?, etc...

A quick test: 
call -r <port_number_as_stated_in_axports> <call_of_other_packet_bbs>
Example: call -r ax1 ab0cde-1
If you can connect to the other bbs and you can give commands and it responts ok,
then the basic ax25 is ok and the TNC/radio is most likely ok. (You can go directly to step 4 if you like)

Step 2: KISS ok?
If you use the Tiny-2 original firmware, is the TNC really in KISS mode?
Sometimes the Tiny-2 firmware jumps back to 'normal mode' when the computer restarts.

If so, try this little script in the beginning of your ax25 startup script.
(add the lines in the beginning of the script before any kissattach ....)

#Set TNC in KISS mode.
echo -ne "kiss on\r" > /dev/ttyS0
echo -ne "restart\r" > /dev/ttyS0
# 3 seconds delay to allow TNC to restart before we go on
sleep 3
#

(If you are using a KISS only firmware for TNC2 and TNC2-clones, KISS is always on)

Reboot and try the quick test in step 1 again to test the connection.

Step 3: Signal levels between TNC and radio.

There are three levels to check:
1. Signal level from the radio to the TNC. (This level is often ok and it is not critical)
2. Signal level from the TNC to the radio. (Often wrong. Is it set to get the correct deviation?)
    (Max 5 kHz deviation, some say 3 kHz deviation is the optimal level)
3. Carrier detection level in the TNC. (Often ok. See the TINY-2 docs how to do that.)

Do the test in step 1 again.

Step 4: FBB setup ok?
Check the file port.sys
Do you get any error messages when you are starting the ax25-stuff or fbb?
grep ax25 /var/log/messages | less
grep fbb /var/log/messages | less

You can also mail me your setup files if you want help to 'check and debug' them.
(axports, ax25d.conf, port.sys, startup-script and nrports + node.perms if you have netrom configured)

73 de SM7LKS, Bo

----- Original Message ----- 
From: "Barry White" <bewhite at bigpond.net.au>
To: "List for the LINUX version of FBB" <xfbb at f6fbb.org>
Sent: Friday, May 09, 2008 8:49 AM
Subject: [xfbb] AX25-->FBB failure


> Hello all,
>           I have been having a problem which I thought was RF interference.
> I would try to connect to the VK2WI BBS and it just did not seem to be 
> there, no response at all.
> I happened to be at the remote site of this BBS when another BBS tried 
> to connect and I was watching the listen -artc8 screen.
> 
> It displayed the SABM packets but the BBS did not respond with an RR.
> The TNC is a Tiny 2 Kiss eprom. As AX25 obviously had received the SABM, 
> otherwise listen would not have displayed it, what then is going on in 
> FBB or AX25 ?  It does not always happen and there were no other 
> connected stations on that port or the other port.
> 
> Because I have seen this when not at the site fairly often then while it 
> is intermittant it is a significant problem.
> The port concerned is on com2 and irq 3 and I am using Knoppix in that 
> machine.
> 
> I have also seen on another xfbb m/c that my BBS connects to another BBS 
> and it responds normally with its SID and sends the > but the m/c acks 
> the > it received but does not respond with its SID so they just sit 
> there sending RRs to each other every 20 seconds or so.
> 
> This failure looks similar to the example above but it is a different BBS.
> 
> Any ideas ?
> 
> Barry VK2AAB
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