[aprssig] Error checking within APRS packets

[Bill V WA7NWP]

> corrupted packets.

FWIW - Packets on the serial link between a KISS TNC and the PC are
not generally CRC protected.  At one time I was running a long serial
link to the TNC, about 50 feet, and running HF packet at the same
time.  It was a strange coincidence that I'd see garbage packets
coming in when ever the HF was transmitting...

I believe some of the more advanced KISS protocols would protect against this.

73
Bill - WA7NWP