[GRAAP-WG] Modification to the wiki Page on Renegotiating an established Agreement

[Michael Parkin]

Hi Karl,

Sorry, I have a couple of quick questions/observations... Apologies  
in advance if I have misunderstood anything in your email as  
sometimes happens.

On 24 Aug 2007, at 11:54, Karl Czajkowski wrote:

<snip/>

> ... However, due to the non-binding nature of
> these signals and the assumption of bounded rationality (we can ignore
> the possibility of bluffing and other psychological strategies), I am
> not sure these differences are significant.  For privacy, one could
> imagine secure advertisement channels (with authorization) to further
> blur the boundaries.

Are you saying that 'bluffing and other psychological strategies' can  
be ignored in the negotiation protocol that is used or in the  
negotiation strategy of each participant? For me, these two aspects  
of reaching agreement are orthogonal, just like they are in (for  
example) contract law.

> Furthermore, 2PC can be synthesized with two WS-Agreement round-trips
> and an appropriate domain-specific agreement semantics. So, either
> advance reservation, combined with the right cost/penalty model, or
> the underlying invitation system can both look like 2PC in practice:
>
>  1.a.  initiator offers advance reservation, OR
>  1.b.  advertiser publishes interest
>
> after this first stage, both parties are aware of interest and primed
> to negotiate...
>
>  2.a.  responder accepts (or rejects) reservation offer, OR
>  2.b.  initiator offers against advertisement (or ignores it)
>
> after this stage, one party is obligated to satisfy and the other has
> a choice to make... (For the advance reservation, the initiator has a
> choice because the reservation includes a cost model with cheap
> cancellation under reasonable deadlines).
>
>  3.a.  initiator offers claiming agreement (or cancels  
> reservation), OR
>  3.b.  responder accepts offer (or rejects it)

So far you have the messages: offer, advert, cancel, accept and  
reject... all of which are clear to me.

But can you explain what the 'offers claiming agreement' step (3a)  
is? I'm sorry, I don't understand what this means - is it an offer,  
accept or another message being sent from the initiator to the  
responder?

<snip/>

> p.s. I will add that the fundamental challenge I see for GRAAP-WG and
> WS-Agreement is that everyone approaches it with the same natural (but
> incorrect) intuitions about trust, signalling, and consensus.

Can you explain some more about what you think these shared (but  
incorrect) intuitions are?

My intuition is to a) trust no-one, b) assume messages ('signals')  
can be lost, duplicated and re-ordered and c) assume that consensus  
may or not be reached - it depends :-). Are these the same as yours  
and/or GRAAP-WG's?

Thanks,

Michael.