[aprssig] Maximum APRS Packet Lengths and 3rd party use?

Robert Bruninga bruninga at usna.edu
Wed Nov 30 11:07:27 CST 2016


➢ #1) I vote for the shorter, cleaner, human readable, third party format
FWIW.

I’m going to ask Pete Loveall or Steve Dimse to remind me once again, if
general Purpose THIRD PARTY format can be used on the air and will get into
or through the APRS-IS without conflicting with the APRS-IS use of 3rd party
as a loop filter.  I believe this restriction on general purpose use of 3rd
party went away when the QAR and TCPIP constructs were implemented.?

> it as being 80-columns?)!

To clarify, 80 columns has nothing to do directly with any specific APRS
format directly.  But someone asked why all the packet formats have limits.
And the answer is derived from the original display width of the IBM PC AT
of 80 chars.

>From that 80 column width, the actual APRS format limits vary significantly
so that the actual displayed data as parsed was within that limit.

So to translate, you have to adhere to the SPEC limits for each format
individually.

And the limits are there so that anyone who transmits beyond those lengths
has been made aware that almost all other APRS stations will not receive or
display data beyond those limits.  Doing otherwise would obsolete tens of
thousands of users with Kenwood and Yaesu, and all other kinds of hardware
APRS systems.

I wonder if anyone has done a recent DUMP of all station types on the air?
Hummh...

Bob, WB4APR


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