xPL protocol questions

[Gerry Duprey <gerry@xxxxxxxxxxx>]

Howdy All,

I've been reading over the configuration support in xPL -- this is
**great**
stuff.  I had a few questions I was hoping someone could be kind enough to
clear them up for me:

1) Unconfigurable Devices
If a device just flat out cannot support configuration at all,
how should it announce itself.  Should it just skip sending out
the config.app/base and go straight to sending out heartbeat messages?

2) Timeout on Configuration
If a device does support configuration, how long should it keep sending out
config.app/base messages (in lieu of a heartbeat message) if it's not
getting a reply?  For example, I start up and send a config.app out.  Lets
say I send one out every 5 minutes, but I don't get any reply back.  Should
I keep sending config.app out for eternity or wait X heartbeats before
dropping back to any previously saved defaults and start sending normal
heartbeat messages.

3) Can an app request configuration data (sending config.base/app) at any
time or only during initial device identification/discovery?

4) Handling Locally Saved config data
The xPL docs suggest a device should try to save config settings, if
possible, and restore them.  If I have a device capable of doing that,
should I restore the config and then still broadcast config.app?  If I get
a
config.app reply, should I dump all my stored config data and use only what
I get back in the reply (like when you get a group= and are supposed to
dump
all existing groups) or should data be merged (items supplied in the reply
overwriting those previously loaded and items not in the reply remaining
untouched)?

5) config.base vs config.app
What is the difference between config.base and config.app?  Should they
just
be used with the same rules as hbeat.base and hbeat.app?

On non-configuration items

1) Are requests for status mandatory in xPL?
2) Is the key for asking for them that the message schema class
unimportant,
only that the type is ".request"?  Or should the schema class be
checked as
a valid schema class for this device and then the .request processed?  Are
there any other required types of a schema class?
3) Can you send status requests out to target=* or must they always be
directed?
4) Do responses to a status request always have to have a target=* or can
they choose to direct it at a certain target (presumably, the source)?
5) Is their some suggested time limit a client sending a status request
should allow before assuming it's not going to get a request?  Or should
such requests be consider async -- you may not get a response, may get one
response or many (i.e. responses are, at best, loosely coupled to requests
for status)?
6) Can the target= on a trigger message ever be a specific target or must
it
always be a wildcard?

Sorry for all the Qs -- I am reading the protocol docs, but these areas are
either note covered or I'm missing them (my apologies -- I'm re-reading the
docs over and over trying to see if I missed any of this).

Thanks for any help!

Gerry

--
Gerry Duprey
Ann Arbor, MI 48103
http://www.cdp1802.org