[aprssig] ax25 v 2.2

[Robert Bruninga]

>AX25 version 2.2 limits the number of digipeaters to 2.  
>Has anyone implemented 2.2?  What effect would the 
>2  digipeater limit have on APRS?

The people who are writing 2.2 do not seem to recognize
 APRS or other forms of UI communications.  We agree
completely that more than 2 hops for connected protocol
is not wortth trying on a typical shared channel.  But
the SPEC should not be used to try to overcome dumb
uses of the hardware.

I can imagine several scenarios where multiple level 2 hops
over 2 may be useful and may be quite reliable.  Yes, these
scenarious are RARE and unusual, but the spec should
allow them!   

Further, although APRS works best at about 2 hops in very
dense areas of 60 to 100 stations, it can easily use more hops
in many low density applications.  Again, the hardware and firmware
of a TNC should allow greater hops for RARE or unusual
applications.  Besides one-way UI packets like APRS are
about equally reliable over FOUR hops as a connected
packet is at 2 hops.  THus if these spec writers are hard
set on a 2 hop limit for connected protocol, then they
must allow a 4 hop UI as a minimum equivalent limit for UI..

Who do we get this common sense to?
de Wb4APR, Bob


Mike



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