[nos-bbs] AXIP networking

[Barry Siegfried]

["George F. VerDuin" <k8rra at ameritech.net> wrote]:

> Consider this:
> Access to a particular tunnel requires a unique call ID, the only
> uniqueness I can give this ID is with SSID, and so the SSID list
> becomes very crowded as you enter more tunnels.

Yes, and that becomes particularly problematical when you have
"lots" of tunnels.

> Further -- if mycall is used it is immediately ambiguous so omitting
> the call is a no-solution because it violates the uniqueness rules
> for digipeating.

This is an interesting topic.  I believe that its code and the code
in Linux to do that are similar in functionality, which is that each
AX.25 neighbor (or user) source to the machine that cross-interface
digipeats has to know the callsign of the interface that faces toward
the destination (not the source) ahead of time and then use that
callsign in the digipeater string.  The code then does some fancy
callsign substitution in the digipeater string using the callsign
that is assigned to the interface on the source side of the circuit
for the return path on the destination side of the circuit.

Since JNOS has an AX.25 routes list, it can be utilized to "force"
an AX.25 route in a JNOS AX.25 neighbor to such a cross-interface
digipeating machine to a callsign it can't directly "hear" on an
interface.  But Linux appears to have no such facility so it appears
that the Linux digipeating code can't really work with a Linux
AX.25 neighbor.

Interestingly, there are solutions available using the AX.25 routes
list which eliminate the requirement that each callsign assigned to
an AX.25 (AXIP or otherwise) interface be unique for cross-interface
digipeating purposes.  It requires some code modification to both
ax_recv() and to give the AX.25 routes list a few more "smarts"
than it already has.  This *could* be a solution to the limitation
that there are only 16 SSIDs available for any given callsign.  If
(and when) Maiko becomes interested in this sort of thing, I'll be
happy to discuss it with him off-list.

73, de Barry, K2MF >>
           o
          <|>      Barry Siegfried
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