Network Connections

Network Connections
[ Home ] [ Up ]

Clients

Using javAPRS with static data files adds a bit of animation, but isn't anything that couldn't be done with other internet systems. Where things really get exciting is using javAPRS to connect to live data streams. Net connections are specified with the dataFile parameter.

<PARAM name="dataFile1" value="netc:1234:anAPRS-IS.server.net">

The "netc" informs javAPRS that this is a network data stream rather than a file. The number between the colons is the TCP/IP port number of the server port. The last part is the address of the server. Due to security limitations of Java, this MUST be the same server as the codebase of javAPRS.

<PARAM name="dataFile1" value="net:anAPRS-IS.server.net">

This is another version of the net definition that assumes the port number of 14579.

<PARAM name="sendLogin" value="false"> (default true)

javAPRS defaults to sending a "read-only login" string to the host at connection time. This switch allows you to turn that off if you are going to a non-standard APRS server.

Servers

javAPRS 2.0 supports acting as a read-only server to other javAPRS clients. javAPRS compresses all posits to Mic-E and passes all weather, object, and item packets (after compressing the path and lat/long).

<PARAM name="dataFile1" value="net:1234:127.0.0.1">

This format of the net: dataFile value includes a port number. This tells javAPRS to begin listening on that port for connections. This port must be available and on the same machine that javAPRS is located on.

<PARAM name="cacheTime1" value="30">

This is the value, in minutes, that the specified port will go back in time to transmit posits, weather reports, objects, and items at connection.

This is the server applet definition that I use to support my web site:

<applet code="javAPRS.class" codebase="c:\javaprs"
  height="400" width="600" id="javAPRS">
  <param name="drawVectors" value="true">
  <param name="mapList" value="JWORLD^World ">
  <param name="showMapLabels" value="true">
  <param name="dataFile1" value="netc:1234:127.0.0.1">
  <param name="dataFile2" value="net:1234:192.168.0.1">
  <param name="cacheTime2" value="30">
  <param name="purgeCache" value="1440">
  <param name="showNewStations" value="false">
  <param name="trackstations" value="false">
  <param name="tracksort" value="false">
  <param name="showstationnames" value="false">
  <param name="dosMap" value="JWORLD.mp">
</applet>

The bold lines are important to keep the size and overhead of the applet down. The codebase printed here is make-believe.

APRS is a registered trademark of APRS Software and Bob Bruninga, WB4APR.