[Dundi] Precache documentation is somewhat confusing

[Kevin P. Fleming]

I'm not quite clear on how precaching is supposed to be set up... Here's 
a simple scenario.

There are three servers, A, B and C.

A has PSTN connectivity, and IAX to B and C. It has no direct 
"termination" numbers, there are no end-nodes connecting to it. A 
publishes DUNDi routes for PSTN connections to B and C.

B and C have end-nodes connecting to them, but no PSTN connectivity, 
only IAX to A (and each other, of course). B and C publish DUNDi routes 
for the DNs associated with their end-nodes.

I'd like to have B and C "precache" their routes into A, but I can't 
find a combination of settings that will work. On B and C, server A is 
defined as "model=symmetric" and "precache=outbound", but this fails to 
load. The comments about conflicting model and precache settings in the 
sample dundi.conf file are less than understandable, at least to me.

Can someone explain the limitations of the current precache code?