[aprssig] AX.25 'H' flag

scott at opentrac.org scott at opentrac.org
Sun Nov 13 21:19:02 CST 2005

Maybe I've been staring at code too long, but I can't make sense of this
part of the AX.25 spec:

The H bit is set to "0" on frames going to a repeater. The repeater changes
the H bit to "1" before it retransmits
the frame. Stations monitor and repeat frames that meet the following

a) the frame is addressed to this station in a repeater address subfield;
b) the H bit in its repeater address subfield is 0; or
c) all previous H bits are set to one.

Is that 'or' in B supposed to be there?  Doesn't make sense to me.


More information about the aprssig mailing list