Fun with Filters
- If you get the latest development version with the d/ digipeater filter
fix, you can have some fun with filters via Control-G.
If you want to see the RF stations, use b/* -d/TCPIP/TCPXX as your
filter. The b/* (an internal APRSISCE/32 filter extension) says give me
everything, and the -d/TCPIP/TCPXX (don't miss the minus) says to
exclude those packets with a used TCPIP or TCPXX in their path. Voila -
non-Internet (theoretically RF) station packets!
If you want to see just the Internet station packets, use d/TCPIP/TCPXX
as your filter.
And using another APRSISCE/32 internal filter extension, give a try to
d/TCPIP +m/100. While the traditional filter implementation ORs all
terms together and uses minus to exclude some subset of the hits,
APRSISCE/32 continues to OR all terms together, supports the minus to
exclude a subset, but adds a PLUS term specification. Plus terms are
AND'd together so in order to pass a filter with plus terms, the packet
must match ALL of them.
Consider also something like d/TCPIP +a/latN/lonW/latS/lonE (with
appropriate substitutions of course). Or even d/TCPIP +b/KJ4ERJ* (with
an open mind for the upcoming -IS to RF Igate filters). And throw on a
+m/50 if you want to constrain that one a bit more. Or to be completely
bizarre, make it d/TCPIP +b/KJ4ERJ* -m/50 and think on what you should
And not related to IGating, but for remotely observing your IGate's
activity via the -IS, try a filter of e/KJ4ERJ-1 (substituting your own
IGate's callsign-SSID, of course) or e/KJ4ERJ* (if you run more than one
-SSID as an IGate). If you're not using an IS/Local-Server port, then
you'll only see those packets that your IGate delivered first to the
APRS-IS, but at least you have some capability of filtering for your own
Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
PS. And in relation to the recent discussions of some form of graphical
filter display, give some thought to how the filters above might be