Re: Proposed Up/Down protocol description

[Robert Loomans <robertl@apnic.net>]

> I still believe that msg_ref is enough for replay protection (and
> synchronization too), and that that is the minimum we need - no need to
> clock syncs and the rest.

If, and only if, the server/parent retains the last msg_ref used
indefinitely.

The timestamps and the time windows are to reduce the burden on the
server to remember state.

In the case that the child is rebuilt, it makes re-starting
communications easier... otherwise the child would have to do a search
for the next msg_ref.

>>> Hmmm. So the presence of a tag depends on the content (!) of another
>>> tag? That seems weird...
>>
>> but is useful in the described algorithm
> 
> I'm still not convinced that we need that algorithm (see above).
> 
> OTOH, I wonder what Byron would say to the above conditional presence,
> as I think it prevents automatic schema validation.

Optional elements and attributes definitely can be expressed in Relax NG
schema (not sure about XML Schema, but I would be surprised if it didn't).

Rob

-- 
Robert Loomans                                 Email:  robertl@apnic.net
Programmer/Analyst, APNIC                      Phone:    +61 7 3858 3100
http://www.apnic.net                             Fax:    +61 7 3858 3199

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