On Thu, Dec 20, 2012 at 07:39:12AM -0800, we recorded a bogon-computron collision of the <[email protected]> flavor, containing: > Curt, the fact that LOTWSW is originating from my station seems correct to me > and consistent with what was done in the past with > the?xastir/data/nws-stations.txt file. ?My understanding is Xastir pulls > these warnings that you specify in that file and broadcasts an object over RF > and the internet when these warnings take effect. ?I like the feature and it > is quite useful to people in the area. ?
No, this is not entirely correct. When you put something in .xastir/data/nws-station.txt, it allows Xastir to gate those objects from APRS-IS to RF as third party packets. Third party packets come from your station, but are not interpreted as *originating* from your station. The LOTWSW object from January (the last time it was heard on APRS-IS and therefore aprs.fi) is showing as originating from your station, which is wrong. Third party packets that have been plucked from APRS-IS and gated to RF should never then be re-gated back to APRS-IS by an IGate. All compliant igate software will decline to upload packets that have already passed through APRS-IS (otherwise there'd be serious looping problems). Xastir does not munge the objects from APRS-IS before it gates them as third party. It adds third party headers and then just transmits. Therefore, the old LOTWSW packet we're seeing on APRS-IS has almost certainly been improperly gated back to APRS-IS after you transmitted it as third party traffic. Are you actually seeing your station transmitting LOTWSW objects to RF right now that are truncated? Or are you just looking on aprs.fi to see the object? If you're only looking at aprs.fi, be aware that the single object that's recorded there is almost a year old, and may have been gated back to APRS-IS by a misconfigured igate. The truncation may well have happened there, not in your station. In fact, I'm close to certain of it. > Just want to fix the comment truncation a bit. First be absolutely certain you actually *have* a comment truncation problem. Remember that lots of people have used Xastir to gate weather alerts and objects back to RF, and a glaring error like the truncation of almost the entire comment field (which usually also contains information to allow plotting of the area to which the object is connected) would have been noticed before. Xastir should be retransmitting the object it hears from APRS-IS with no modification whatsoever, and in my experience it does so. To check this, don't look at APRS-IS, because your transmitted third party traffic should NEVER make it back there unless you have a broken local igate, and if it does you can't trust the gate that put it there. Watch your outgoing packets window for packets going out to your TNC. If you see truncated packets in the outgoing object there, then make certain that the truncation is happening locally --- i.e., compare the outgoing third party packet with the incoming weather object from LOTWSW. Unless you see that Xastir has received an unmolested object from LOTWSW and then transmitted it to RF completely mangled, the problem is elsewhere. > Do you think the object should not have an originating ham station? The third party packet originates from your station, but the actual payload originates from LOTWSW, and properly written APRS clients read them that way. Basically, the third-party format encapsulates the entire packet from the originating station (including originating call sign) and wraps them in an extra bit of data that shows the *transmitting* (in addition to the originating) station. That there is a single packet stored at aprs.fi from a year ago with your station showing as the originator suggests that some other igate may have stripped the third-party header the wrong way and ignored the fact that the original had already come from APRS-IS. Doing so, it probably gated the packet back to APRS-IS as if it came from you, not the originating station. It could have done this due to a bug, or there could have been some sort of corrupted packet issue that confused it. That there is only one recorded position in the aprs.fi database further suggests a fluke rather than a completely broken igate. -- Tom Russo KM5VY SAR502 DM64ux http://www.swcp.com/~russo/ Tijeras, NM QRPL#1592 K2#398 SOC#236 http://kevan.org/brain.cgi?DDTNM echo "prpv_a'rfg_cnf_har_cvcr" | sed -e 's/_/ /g' | tr [a-m][n-z] [n-z][a-m] _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
