Traffic Monitoring on the Internet

We recently had a discussion among the APRS users in Denver on the apparent lack of Internet Gateway Stations in some parts of the state.

I have been working on expanding some of the capabilities for AprsNetSpy (ANS) and realized I was 90% of the way towards being able to track this type of activity. There are numerous station that send in data to the net that are not I-Gates, yet they appear in the location in the packet string that identifies them as such. However there is something on APRS-IS that gives further identification on i-Gating stations. ANS uses these Q constructs to attempt to identify actual I-Gates. If a station is identified with these Q constructs:

Then the station is identified as a true i-gate. All other designations:

Are considered to be non, i-gates. When an i-gate transmits the packets of a third party received via the local RF network, it should have one of the accepted constructs. Periodically, an i-Gate will generate a packet from their own station to ID, Beacon, send in weather collected at their location. When that happens, that single packet is considered to have NOT been i-Gated into the network since it was never actually on the outside RF environoment. So, the counts for i-Gates only refer to packets they relay into the net from RF, not those packets they generate locally on their systems.

ANS attempts to determine if the identifier of the I-Gate is actually an amateur radio station. It does this by checking the format of the I_Gate identifier to ensure it has only one numerical character in it (SSIDs don't hurt the check).

A proviso ... when a station is first identified as an I-Gate, it is almost always repeating someone else's traffic. And so, there isn't any position data. Each time ANS discovers an I-Gate, it looks through the data it has been accumulating on ALL stations. If it finds a call sign match for the I-Gate among regular packets and that packet identifies the location of that I-Gate station, then the information about the I-Gate (which is different from a general callsign's information) is updated with whatever information can be discovered from that location packet. What this means is that it is likely that the first packet seen from an I-Gate is NOT a packet containing the I-Gate's position information. So, no position information will be available immediately. Run the program for 15 or 20 minutes and most I-Gates will send along an information packet of some kind that includes their location.

Below is a map of I-Gates within 500 kilometers of 40 degrees north by 105 degrees west (near Lafayette, Colorado and I-25). And below that is the Network printout for all data. The actual APRS-IS server:port and filter are shown at the bottom of the table.