Somebody else is using my call sign in aprs.fi

[Dennis Ramos]

Somebody else is using my call sign in aprs.fi.  What should I do?  Is there somewhere I can report it to?

[Heikki Hannikainen]

On Tue, 13 Oct 2020, Dennis Ramos wrote:

> Somebody else is using my call sign in aprs.fi.  What should I do?  Is there somewhere I can report it to?

Hi,

It depends on how exactly it is being used. Please let us know what is
your callsign?

Sometimes this happens due to a typo (someone makes a 1-letter mistake in
entering their own callsign). In this case you or I can just find a way to
contact him and ask him to fix the config issue. Less often it is
intentional, which more difficult, and then the actions depend on whether
it is being used on RF or just on the Internet.

- Hessu

[bigpi...@gmail.com]

i had the same, several times.

first few times it was malicious and i don't even use APRS,

i eventually managed to find someone involved and got the abusive comments and call sign removed,

recently i checked again after over a year and i found my call sign again as a -1

so i either have a fan club or it's a mistake,

not sure how you can contact a person using your call sign though to tell them..

[Dennis Ramos]

My call sign is KK6YHI and I live in Northern California.  When I signed up in aprs.fi,   I end up getting KK6YHI-10.  I noticed that there's KK6YHI and KK6YHI-8 stations on the same location in Southern California.  They are both active if you look it up.   Isn't that a violation against FCC Rules and Regulations?

[Heikki Hannikainen]

Hi,

I think this KK6YHI case is due to packet corruption. If you'll look at
the info pages here, specifically the callsigns below the title "Stations
near current position of KK6YHI":

https://aprs.fi/info/a/KK6YHI-8
https://aprs.fi/info/a/KK6YHI

it appears that there are a *lot* of slightly different callsigns
appearing at almost precisely that location (just within 50 meters!).
JK6YHQ, KK6YHQ, KK6YPQ, KK6YHR. Differing only by a few bits.

So I'd suspect the link is a bit marginal, and then one of the igates or
digipeaters does not do correct CRC checking for received packets (or has
"PASSALL ON" setting which disables CRC checking), and then the
incorrectly decoded packets are forwarded to the APRS-IS. aprs.fi is
simply showing what it gets from there.

If you'll then sequentially click all of those bogus callsigns, and look
at the "Last path:" to see which igates and digipeaters they went through,
you can try to find a callsign that appears in all packets. That's most
likely the place where the corruption happens. I have a candidate
callsign already. :)

Then someone could try to reach out to the owner of that igate, find his
email address, or send some APRS messages if he's using a
messaging-capable APRS device. And very gently and kindly explain that
there might be an issue, and ask him to check his settings.

I'm a bit busy, if there's someone local in California who could try to do
this exercise, that would be splendid?

- Hessu

On Wed, 14 Oct 2020, Dennis Ramos wrote:

> My call sign is KK6YHI and I live in Northern California.  When I signed up in aprs.fi,   I
> end up getting KK6YHI-10.  I noticed that there's KK6YHI and KK6YHI-8 stations on the same
> location in Southern California.  They are both active if you look it up.   Isn't that a
> violation against FCC Rules and Regulations?
>
> On Wednesday, October 14, 2020 at 12:52:19 AM UTC-7 bigpi...@gmail.com wrote:

> i had the same, several times.first few times it was malicious and i don't even

> use APRS,
> i eventually managed to find someone involved and got the abusive comments and call
> sign removed,
> recently i checked again after over a year and i found my call sign again as a -1
> so i either have a fan club or it's a mistake,
>
> not sure how you can contact a person using your call sign though to tell them..
>
>
> On Wednesday, October 14, 2020 at 7:22:06 AM UTC+1 Heikki Hannikainen wrote:
> On Tue, 13 Oct 2020, Dennis Ramos wrote:
>
> > Somebody else is using my call sign in aprs.fi.  What should I do?  Is
> there somewhere I can report it to?
>
> Hi,
>
> It depends on how exactly it is being used. Please let us know what is
> your callsign?
>
> Sometimes this happens due to a typo (someone makes a 1-letter mistake in
> entering their own callsign). In this case you or I can just find a way
> to
> contact him and ask him to fix the config issue. Less often it is
> intentional, which more difficult, and then the actions depend on whether
> it is being used on RF or just on the Internet.
>
> - Hessu
>

> --
> You received this message because you are subscribed to the Google Groups "aprs.fi" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to
> aprsfi+un...@googlegroups.com.
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> ups.com.
>
>

- Hessu

[Una Smith]

>I'm a bit busy, if there's someone local in California who could try
>to do this exercise, that would be splendid?

I'll have a go at it.

Una

[MJ Inabnit]

been reading this thread. I admit that I am confused. If this device
is being used via tcp/ip, how is it's packets <broken or not> being
retransmitted over the air?

I too spotted the likely suspect. thank you for helping me understand
that important data!

73
j

--

wishing you well
Jaye, ke6sls--via the toshiba w/thunderchicken

[Heikki Hannikainen]

The corrupted / broken packets are being originated on RF, using some
other callsign, but sometimes due to the packets getting decoded wrong,
some of them due to bad luck get decoded as KK6YHI (and a number of other
callsigns which closely resemble it).

Apparently the real owner of that callsign then is using aprsdroid only on
the APRS-IS.

> To view this discussion on the web visit https://groups.google.com/d/msgid/aprsfi/3227904b-817d-0ae5-0cbd-80b599ef7da1%40arrl.net.
>

- Hessu

[Dennis Ramos]

Thank you Hessu for a great explanation.  I now understand how it could happen.  Following your process, it looks like it is KF6ILA-10 that may have the issue. Am I right?

Una, thank you for getting on this.  I'm fairly new to APRS.

73,

Dennis KK6YHI

[Una Smith]

The offending station is now off the air and will stay off until the problem is resolved.

The packets brought to this group's attention by KK6YHI were the tip of an iceberg. A VHF station was transmitting an enormous number of packets, most "dropped on the floor". A few packets were decoded by receiving stations, sometimes with errors. Decoded packets were digipeated locally and gated to the internet. A tiny fraction met criteria for display on aprs.fi. On aprs.fi the iceberg is evident as far back as April 2020; it may have existed for years prior. There appear to be multiple contributing factors including equipment, programming, location, application, and inattention or silence in the local APRS user community.

Following Hessu's request for assistance I reached out to the owners of the transmitting station and the iGate. The station owner appreciates being made aware of the problem, which was entirely unintentional.

Una

>To view this discussion on the web visit https://groups.google.com/d/msgid/aprsfi/3227904b-817d-0ae5-0cbd-80b599ef7da1%40arrl.net.

[Heikki Hannikainen]

Thank you Una! Good work.

Usually these are just accidental misconfigurations, sometimes software
bugs. Just needs to be tracked down and a little help to correct the
issues.

>>>> My call sign is KK6YHI and I live in Northern California.??? When I
>>>> signed up in aprs.fi,??? ???I
>>>> end up getting KK6YHI-10.??????I noticed that there's KK6YHI and KK6YHI-8
>>>> stations on the same
>>>> location in Southern California.??? They are both active if you look it
>>>> up.??? ???Isn't that a

>>>> violation against FCC Rules and Regulations?
>>>>
>>>> On Wednesday, October 14, 2020 at 12:52:19 AM UTC-7 bigpi...@gmail.com
>>>> wrote:

>>>> ??????????????? i had the same, several times.first few times it was

>>>> malicious
>>>> and i don't even

>>>> ??????????????? use APRS,

>>>> i eventually managed to find someone involved and got the abusive
>>>> comments and call
>>>> sign removed,
>>>> recently i checked again after over a year and i found my call sign
>>>> again as a -1
>>>> so i either have a fan club or it's a mistake,
>>>>
>>>> not sure how you can contact a person using your call sign though to
>>>> tell them..
>>>>
>>>>
>>>> On Wednesday, October 14, 2020 at 7:22:06 AM UTC+1 Heikki Hannikainen
>>>> wrote:

>>>> ??????????????? On Tue, 13 Oct 2020, Dennis Ramos wrote:
>>>>
>>>> ??????????????? > Somebody else is using my call sign in aprs.fi.??? What
>>>> should I
>>>> do???? Is
>>>> ??????????????? there somewhere I can report it to?
>>>>
>>>> ??????????????? Hi,
>>>>
>>>> ??????????????? It depends on how exactly it is being used. Please let us
>>>> know
>>>> what is
>>>> ??????????????? your callsign?
>>>>
>>>> ??????????????? Sometimes this happens due to a typo (someone makes a
>>>> 1-letter
>>>> mistake in
>>>> ??????????????? entering their own callsign). In this case you or I can
>>>> just
>>>> find a way
>>>> ??????????????? to
>>>> ??????????????? contact him and ask him to fix the config issue. Less
>>>> often it is
>>>> ??????????????? intentional, which more difficult, and then the actions
>>>> depend
>>>> on whether
>>>> ??????????????? it is being used on RF or just on the Internet.
>>>>
>>>> ??????????????? - Hessu

>>>>
>>>> --
>>>> You received this message because you are subscribed to the Google
>>>> Groups "aprs.fi" group.
>>>> To unsubscribe from this group and stop receiving emails from it, send
>>>> an email to
>>>> aprsfi+un...@googlegroups.com.
>>>> To view this discussion on the web
>>>> visithttps://groups.google.com/d/msgid/aprsfi/bada4411-399b-47aa-a4cd-002e1e337b85n%40googlegro
>>>>
>>>> ups.com.
>>>>
>>>>
>>>

>>> ??? - Hessu

>>>
>>
>>
>> --
>>
>> wishing you well
>> Jaye, ke6sls--via the toshiba w/thunderchicken
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "aprs.fi" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to aprsfi+un...@googlegroups.com.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/aprsfi/3227904b-817d-0ae5-0cbd-80b599ef7da1%40arrl.net.
>
> --
> You received this message because you are subscribed to the Google Groups
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> To view this discussion on the web visit

> https://groups.google.com/d/msgid/aprsfi/20201016173859.GA11066%40att.net.
>

- Hessu

[Ed Fardos]

fwiw, I've seen invalid/incorrect/corrupted callsigns come through on the radio. I don't
think the callsign is included in the packet CRC? just the payload? One flipped bit could
tweak KM6XXX to KM6XYY.

If there are dozens of packets, then yah, bad configuration.

imho,
-craig

[Heikki Hannikainen]

Hi,

On Tue, 20 Oct 2020, Ed Fardos wrote:

> fwiw, I've seen invalid/incorrect/corrupted callsigns come through on
> the radio. I don't think the callsign is included in the packet CRC?
> just the payload? One flipped bit could tweak KM6XXX to KM6XYY.

The callsigns are naturally included in the FCS, Frame Check Sequence
(CRC).

http://www.tapr.org/pdf/AX25.2.2.pdf section 3. Frame Structure. The frame
is actually a HDLC frame. 3.7 says "The Frame-Check Sequence
is calculated in accordance with recommendations in the HDLC reference
document, ISO 3309."

https://en.wikipedia.org/wiki/High-Level_Data_Link_Control#Structure

"The frame check sequence (FCS) is a 16-bit CRC-CCITT or a 32-bit CRC-32
computed over the Address, Control, and Information fields."

But then again, in common TNC setups, the HDLC framing is done by the KISS
TNC. Plain vanilla KISS protocol used on a serial link does not have a
CRC, so you can have data corruption on the serial link! KISS extensions
for CRC do exist and are used in many setups.

- Hessu

[Una Smith]

Thanks, all.

Yes, a prime suspect is KF6ILA-10. However, that station is the key repeater for an enormous area. That all identified corrupted packets go through it does not prove it is the source of the corruption. The station is up a forest road on a mountain and has been in operation since 2008 without modification. Now is the first time anyone has noticed a problem, which suggests a relatively new condition. The station owner is aware now that KF6ILA-10 may be corrupting packets or permissively repeating corrupted packets, and will be addressing the question.

Without monitoring and directly sampling packets over RF I would not attribute cause to any one station. There are too many possible players, some that may not be observable from outside the area. Several persons in the local area are monitoring RF directly, so this will get sorted out.

Southern California is busy with wildfires, so everyone please be patient.

73 de KE5CEP E E

[Dennis Ramos]

Thank you, Una, for reaching out to the offending station.  Thanks once again to Hessu for detailed explanations.  I'm learning more and more everyday!

73,

Dennis

[Frank Caltabiano]

For what it's worth, I got a vanity call recently.  I changed it On APRS.FI and then when I checked my station, there was the same call already there out on the middle of one of the oceans, but was using a different identifier.  It's still ongoing, though it doesnt look like ot has moved in awhile.

To view this discussion on the web visit https://groups.google.com/d/msgid/aprsfi/20201016173859.GA11066%40att.net.