Friday, September 10, 2010

IPv6 support in APRS packet parser - FAP version 1.17

Version 1.17 of the Ham::APRS::FAP APRS packet parser has been released and uploaded to the CPAN. It should appear at the mirrors during the next 24 hours or so. The main feature is IPv6 support in APRS packet path parsing.

What?!? IPv6 support in APRS?

aprsd, and sometimes other software too, sends position packets to the APRS-IS using the qAI Q construct. qAI triggers packet path tracing in the APRS-IS. Each APRS-IS server inserts the hexadecimal source IP address of the previous server to the packet. Now that quite a few Tier2 APRS-IS servers have IPv6 connectivity, even some T2 hubs, IPv6 hex addresses can appear, and they are a bit longer than regular callsigns, and were getting rejected by the parser.


In this case 92E5A2B6 is the IP address of THIRD, and 200106F8020204020000000000000002 (2001:6f8:202:402::2 in normal IPv6 printed representation) is the IP address of T2HUB1 (T2FINLAND happened to be connected to T2HUB1 at the time).

Here's the complete list of changes:
  • Remove / or ' ' from beginning of comment after parsing away PHG, altitude and other optional data
  • Allow hexadecimal IPv6 addresses in APRS-IS paths after Q construct
  • Added tests for uncompressed packet altitude (negative, too)
  • Fixed destination callsign based symbol selection for 'BC'
  • Updated URLs to, etc is also available using IPv6 at

No comments: