[aprssig] Definition of IGate status messages? ("Station Capabilities")

Lynn W. Deffenbaugh (Mr) ldeffenb at homeside.to
Tue Jun 28 09:26:44 EDT 2016

On 6/28/2016 9:00 AM, John Langner WB2OSZ via aprssig wrote:
> This leaves many questions.  Does "number of messages transmitted" mean only
> the APRS "Message" (data type indicator ":") or does it mean any type of
> APRS packet?

For APRSISCE/32 I count only the APRS Message packets for MSG_CNT. And 
only those gated from the APRS-IS to RF for local stations since it is 
afterall an IGate status packet.

> What are "local" stations?  Anything heard over the radio or
> only those we hear directly without going thru a digipeater?

For APRSISCE/32, "Local" is defined as those stations to which messages 
would be gated if any are received from the APRS-IS.  This currently 
means unique stations heard within the past 30 minutes with at most two 
used path hops.

> Do we count
> stations heard in the last hour?  Last 24 hours?  A year ago?

This was completely unspecified as far as I could tell, so APRSISCE/32 
simply counts them per activation.  If the IGate is restarted, the 
counts start over at zero.

> What are DIR_CNT, RF_CNT, RFPORT_ID, ...?

I added DIR_CNT and RF_CNT with comma delimiters to APRSISCE/32's IGate 
status.  DIR_CNT is the count of unique stations received on RF in the 
past 30 minutes with no used hops.  RF_CNT is the total count of unique 
stations received on RF in the past 30 minutes.

> Are the counts since the system started up or are they for some interval?

APRSISCE/32 starts counting at zero for each execution of the program.  
Of course the DIR/LOC/RF_CNTs are instantaneous at the time of transmission.

> Is any of this defined anywhere?  What other statistics are commonly used?
> What new statistics would be useful?

Not that I know of!

I extended the spec while adhering to the key=value,key=value format.  
APRSISCE/32 may also include a PKT_CNT (count of non-message APRS-IS 
packets gated to RF) and possibly a Receive-Only indication if 
transmitting is disabled on the IGate's RF port.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

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