[aprssig] APRS-IS: frames bypassing server filter
hessu at hes.iki.fi
Wed Jul 15 17:56:32 EDT 2020
Looking for qAO would have some side-effects for iGates which have more
than one port, with one being just a receiver (on a different band maybe)
and one a transmit-capable one. It'd have to keep track whether any
non-qAO packets are heard and then re-enable igate support. In non-igate
mode it'd have to check all packets just in case one would be non-qAO.
Some other corner cases may also rise.
But since Wojtek pointed out that the question was more of the academical
type, maybe we can skip the coding part at this point and have one
complication less to worry about. :)
I wonder if rx-only iGates typically implement the qAO construct or just
stick to qAR. I'd run some statistics but it's 1 AM already.
On Wed, 15 Jul 2020, Lynn W Deffenbaugh (Mr) wrote:
> Good catch John!
> So, if the APRS-IS server would look for the qAO on incoming packets on an
> IGate-capable port, they could skip the adding of the packet source to
> whatever they are using to forward future packets out that connection. I
> like the idea. I requires NO changes to the protocol, allows the IGate
> operator (and the software) to indicate in a standard fashion that it is
> receive-only, and the APRS-IS server can take action on information that is
> already being passed. And it doesn't break if the IGate is connected to a
> non-supporting APRS-IS server instance, they'll just continue to receive the
> packets that they receive today.
> APRS-IS server authors, what do you think?
> Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
> On 7/15/2020 9:48 AM, John Langner WB2OSZ wrote:
>> There is already a way for IGate stations to identify themselves as two way
>> or receive only.
>> >From http://www.aprs-is.net/q.aspx
>> qAR - Packet is placed on APRS-IS by an IGate from RF. The callSSID
>> following the qAR is the callSSID of the IGate.
>> qAO - (letter O) Packet is placed on APRS-IS by a receive-only IGate from
>> RF. The callSSID following the qAO is the callSSID of the IGate. Note that
>> receive-only IGates are discouraged on standard APRS frequencies. Please
>> consider a bidirectional IGate that only gates to RF messages for stations
>> heard directly.
>> aprssig mailing list
>> aprssig at lists.tapr.org
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