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Overview

Joey, NV0N, has been working on finding the right configuration for USB Sound Modems like the Tigertronics SignalLink USB to be used for accessing packet BBSes. (APRS setup is a bit different in that it uses "kissattach" and "kissparms".)

Below is a work in progress under Natty. Feel free to edit this page if you have success.

Software

This setup requires these packages:

• libax25 - library for hamradio applications
• ax25-apps - AX25 ham radio applications
• ax25-tools - AX-25 tools
• ax25-xtools - AX-25 tools (X versions) - optional
• ax25spyd - AX.25 traffic analyzer, dumper and spy daemon
• soundmodem - Sound Card Amateur Packet Radio Modems
• rigctl - Rig Control programs
• node - ham radio node (digipeter) application

Configuration Files

Soundmodem config

From /etc/ax25/soundmodem.conf

Notes:

• the IP address can be arbitrary for your testing (in fact, you can just leave it as is)
• replace the NV0N callsign with yours
• replace the hamlib configuration with yours. (123 is a Yaesu FT-897)
• I've added hamlib_params below which you may need to change or delete.

<?xml version="1.0"?>
<modem>

<configuration name="siglink"><channel name="Channel 0"><mod mode="afsk" bps="1200" f0="1200" f1="2200" diffenc="1" filter="df9ic/g3ruh" inlv="8" fec="3" tunelen="32" synclen="32"/><demod mode="afsk" bps="1200" f0="1200" f1="2200" diffdec="1" filter="df9ic/g3ruh"/><pkt mode="MKISS" ifname="sm0" hwaddr="NV0N-8" ip="44.94.11.8" netmask="255.255.255.0" broadcast="49.94.11.255" file="/dev/soundmodem0" unlink="1"/></channel><chaccess txdelay="300" slottime="100" ppersist="64" fulldup="0" txtail="30"/><audio type="alsa" device="plughw:2,0" halfdup="1" capturechannelmode="Mono"/><ptt file="/dev/ttyUSB0" hamlib_model="123" hamlib_params="serial_speed=4800,rts_state=OFF,dtr_state=OFF"/></configuration></modem>

axports

The standard naming convention for soundmodems is sm0

# /etc/ax25/axports
#
# The format of this file is:
#
# name callsign speed paclen window description
#
sm0     NV0N-8  1200    255     2       145.090 MHz (1200  bps)

ax25d

# /etc/ax25/ax25d.conf
#
# ax25d Configuration File.
#
# AX.25 Ports begin with a '['.
#
[NV0N-8 via sm0]
parameters 1    10  *  *  *   *   *
NOCALL * * * * * * L
default 1 10 3 300 10 5 -       root    /usr/sbin/node node %d %s

<netrom>
parameters 1    10  *  *  *   *   *
NOCALL     *     *  *  *  *   *   L
default    *     *  *  *  *   *   0        root /usr/sbin/node node

Node

Edit

• /etc/ax25/node.conf
• /etc/ax25/node.perms

and set your callsign and related fields.

startup script

This is the startup script (I call it packet.sh). Must be run as root/sudo. Advice is to run these manually the first few times until you get no errors. Keep in mind the route commands below need to match what you put into soundmodem.conf above.

# start ax25 with the soundmodem driver using the port
# defined in /etc/ax25/axports
/usr/sbin/soundmodem /etc/ax25/soundmodem.conf -R -M >/dev/null 2>/dev/null&
sleep 1
# TNC Parameters txd, persist, slottime, txtail are done by
# soundmodemconfig and stored in soundmodem.conf
# this adds a route to our soundmodem
/sbin/route add -host 44.94.11.8 dev sm0
# route to the rest of the netrom IP capable nodes
/sbin/route add -net 44.94.11.0 netmask 255.255.255.0 gw 44.94.11.8 dev sm0
sleep 1
# listen for various incoming connects like PMS, node, etc.
# (MUST first be configured in /etc/ax25/ax25d.conf)
/usr/sbin/ax25d
sleep 1
# listen for stations heard
/usr/sbin/mheardd

At this point you should be at a command line and can run

axcall sm0 callsign

where callsign is your local BBS.