[aprssig] Digipeater addresses/spec question

Tue Jul 19 11:07:15 EDT 2011

Hello:

In the APRS specification as well as packets I hear over the air, the
source path header is the following:

Source>Destination, Digi, Digi, Digi:<body>

(TNC-2 format)

Question, are the digipeaters addresses really Source based addresses
as defined in the spec with the addition of special key words (WIDE,
TRACE, etc.)?

If that's the case, why do Source addresses require a SSID while
Digipeater addresses do not?

"In both formats, the SSID may be omitted if it is –0."

[APRS Specification page 94]

-aps (KC2ZSX)