James Ewen wrote: > AX.25 packet rules limit the value of "N" to a maximum of 7. > > Just for clarity to those learning AX.25 by osmosis, the AX.25 packet rules (http://www.tapr.org/pub_ax25.html) do NOT directly limit the value of N to 7, but to 15 (4 bits as shown in 2.2.13.1.1 (A7) and 2.2.13.2 (A21)). This is where the SSID limits of -0 (normally suppressed) to -15 comes from.
What AX.25 DOES directly limit is the number of elements in the PATH of a packet. This is limited to 8 per 2.2.13.3 in the AX.25 spec. This limit does not include the source and destination callsigns (the Address-Field 2.2.13.1). With callsign substitution occurring, a WIDE7-7 packet could become: DIGI-1,DIGI-2,DIGI-3,DIGI-4,DIGI-5,DIGI-6,DIGI-7,WIDE7* This consumes all 8 available path slots according to AX.25. By extension, a WIDE8-8 or WIDE9-9 would run out of substitution spots in the path before exhausting the path, thereby blaming the WIDE7-7 limit on AX.25, but only because of the callsign substitution and traceability of the WIDEn-N paradigm. Lynn (D) - KJ4ERJ - Testing my understanding of the actual limits
