Complete NOSaprs runtime configuration - September 12, 2004 - by VE4KLM

Finally - I present a complete NOSaprs runtime configuration, complete with the binary and all the necessary configuration and support files. This runtime configuration uses JNOS 1.11f on Linux, and is known to work on Slackware 9.1 and Red Hat 9.0 systems. Keep in mind that you will be running an actual JNOS system here (NOSaprs is just one part of it), so this is an opportunity for you to learn about other aspects of packet radio, like having keyboard to keyboard chats, running TCP/IP over packet, connecting to BBS systems and reading the bulletins or leaving mail for other users. In the end, APRS is just another application that rides on top of packet (ax25) radio.

What you need before you try this

Computer with a free serial port (for the TNC), and an ethernet interface. The computer should be running Slackware 9.1, Red Hat 9.0, or similar linux. A text only install is good enough (no kde or gnome needed), so a Pentium 100, 32 Meg Ram, 1 Gig HD is sufficient.

TNC must have a KISS mode or contain a KISS or SMACK eprom. I use a PacComm Tiny-2 MK-2 with a SMACK 1.3 eprom in it. By default, SMACK uses standard KISS until it receives data telling it to go to a higher level, so it will work. I have an old KPC-2 that works, but you need to first run 'minicom', then issue 'cmd:in kiss', then 'cmd:reset', then disconnect minicom, after which point the TNC is in KISS mode. Why KISS ? That is what NOS uses to talk to a TNC.

network and internet connectivity
Make sure the 'slattach' network package is installed on your linux, because JNOS uses SLIP for network connectivity to the rest of the world. The runtime configuration that I have provided is based on the following network layout :

I have a fixed IP address on the internet, my linux box sits behind a firewall/router. The router is, the linux box is In order for the JNOS application to have network connectivity, there is a slip interface on the linux box. The linux side is, the jnos side is You may be asking why I am using the SAME 192.168.1 network for two different interfaces ? The key is to make sure the linux slip interface is configured with the proper netmask AND you need to add a route on the firewall/router that says to use as a gateway to I find it easier to manage my routes this way, you may have your own way of doing this of course. The reason I am giving this information is that my autoexec.nos and slip setup files are based on this very configuration. Your setup will no doubt be different, so here lies the challenge for you to make your network connectivity work for you.

Extracting the archive file

Download the archive file, 'jnos.dist.tar.gz', to '/tmp', run the following commands (as root user) :

  cd /tmp
  gunzip jnos.dist.tar.gz
  cd /
  tar xvf /tmp/jnos.dist.tar
  mv jnos.dist jnos

If everything went fine, you should now have a '/jnos' directory.

Before you run anything - editing the main control file

Most flavours of NOS have one main control file that tells NOS how to run. This file is usually called 'autoexec.nos'. You will need to edit it, and change a few things - such as making sure the proper callsigns are set, coordinates properly reflect your area, etc. Change to the /jnos directory, and use your favorite editor to begin editing the file (ie, 'vi autoexec.nos') as follows :

• Replace all occurances of 've4klm' with your own callsign. If you see a 've4klm-10', then replace the 've4klm' part, leaving the '-10' part alone, unless you know what you are doing and purposely want to use another SSID.

• My system used '/dev/ttyS1' for my TNC. If your device name is different, then you will have to change the value 'ttyS1' to the proper value. Note - in NOS the '/dev/' part of the device name is NOT specified in the attach command.

• Change following entries to reflect the info, coordinates, and interval you want to send to the APRS internet system :

  aprs bc stat
  aprs bc pos
  aprs bc timer

• Change following entries to reflect the info, coordinates, and interval you want to send to RF :

  aprs bc rfstat
  aprs bc rfpos
  aprs bc rftimer

• Change the 'aprs contact' entry or comment it out.

• There are 3 APRS internet servers already configured for you, change them if you want.

• Examine the 'aprs calls ...' entries. Think carefully about what you want to broadcast to RF (if anything).

That should do it ! Hopefully I have not forgotten anything. If you think something needs to be better explained please let me know and I will make the necessary corrections or additions to this page.

IF you had the same identical network setup as mine, you could technically run it now. BUT !!! You will probably have a different setup then mine, whether by choice or not. Which brings us to the next part - likely the most challenging part of this whole exercise - setting up the networking ...

Before you run anything - figuring out and setting up the network

Before running JNOS, we need to setup the SLIP interface. This is done using the 'slipX' script. This only needs to be run once, and typically the contents of the script file are placed in the /etc/rc.d/rc.local (or similar) file, so that the interface is ready immediately after a machine powers on.

The slip interface is straight forward, and likely the only thing you may have to change there is your choice of ip addresses. IF you change them in the 'slipX' startup script, make sure you change the values in the 'autoexec.nos' file as well. If you can get JNOS to talk to linux, then that is a good start. Getting JNOS to talk to the internet is the final result, and this is where it helps to have some linux networking experience. I will leave that up to you.

The big moment - running JNOS (NOSaprs) for the first time

Note - I have not got into the issue of file ownership, I'll leave that up to you to deal with. Pretend you are the root user (which is the only user that can run the 'slipX' script anyways) for this exercise. Just do the following :

  cd /
  sh ./slipX

That's it ! JNOS should now be running. Try to telnet to JNOS ( in my case) from the linux prompt. Try to telnet to LINUX ( in my case) from the JNOS prompt. See if you are connected to the APRS internet system, by running the 'aprs stat' command at the JNOS prompt. Play around with it, let me know if you find any snags in the install, or if you need some help with a particular item. PLEASE - before you email me asking me for help, take a good look at the user manual and the release notes - the answer may be there already. Thanks for your understanding.

Many JNOS users wind up putting a JNOS startup script in /etc/inittab. Do a search on for examples. There should be several good ones on there. I'm still working on this page, fine tuning it so to speak. No doubt it will not be perfect. If you have experiences that will help others to install this, please let me know, I will document it here. Thank you.

* Maiko Langelaar / VE4KLM, September 12, 2004