> > Do the sequence numbers play a role our state machines? I hadn't thought
> so.
> 
> The play is implicit based on the following lock-step constrations:
> 
> - Each peer maintains a single sequence number space for outgoing
> requests.
> 
> - There is only one outstanding outgoing request allowed for each
> peer.  A peer that receives a request accepts the sequence number
> which is last received sequence number + 1 only.

Both of these rules are still maintained whether we have two state machines
or one. Do we change anything? As long as we stick to "one outstanding
request at a time" rule, these rules shall apply as they are.


> This means sequence numbers play a role in our state machine.  Running
> multiple state machines in pararell and independenly would break the
> lock-step constraints.

In my understanding, "lock-step" is about "not having two outstanding
requests issued by the same peer." Based on that, I'd say the lock-step
nature is preserved.

The sequence number processing on incoming messages are done for validation.
Invalid messages are tossed away, valid ones are processed by the state
machine. I don't think we'd have a statement in our state machine
specification that uses the "sequence number" as an input and change the way
state machine runs. 

What do you think?

Alper





> 
> Yoshihiro Ohba
> 
> 
> 
> >
> > Alper
> >
> >
> >
> >
> > >
> > > Yoshihiro Ohba
> > >
> > >
> > > >
> > > > This scheme prevents any special case handling to be part of the
> > > protocol
> > > > specification.
> > > >
> > > > Your suggestion below works too I believe. Though I lean towards the
> > > above
> > > > suggestion, given that it does not special case one type of message
> in
> > > the
> > > > spec.
> > > >
> > > > I remember once mentioning use of a separate state machine for
> pings. I
> > > > don't remember what the feedback was....
> > > >
> > > > Alper
> > > >
> > > >
> > > > > which will end up with the 2*N
> > > > > problem.  On the other hand, it may be possible for the PaC to
> queue
> > > > > the incoming PAR until the ping request is answered.
> > > > >
> > > > > So how about relaxing the third item to:
> > > > >
> > > > > "
> > > > > - When there is an outstanding ping request, all incoming messages
> > > > >   MUST NOT be processed except for ping answer or error request
> sent
> > > > >   in response to the ping request.
> > > > > "
> > > > >
> > > > > Yoshihiro Ohba
> > > > >
> > > > > >
> > > > > > Alper
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > >
> > > > > > > This may be an acceptable operation.
> > > > > > >
> > > > > > > Yoshihiro Ohba
> > > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > Alper
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > Pana mailing list
> > > > > > [email protected]
> > > > > > https://www1.ietf.org/mailman/listinfo/pana
> > > > > >
> > > >
> > > >
> >
> >


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