[Roll] Closing on Ticket #10

[JP Vasseur <jvasseur at cisco.com>]

Dear all,

As a reminder Ticket #10 is related to a node behavior when receiving  
a DIO with an OF that it does not understand / support.

There was a strong consensus for the following option:
> > Option 1: The node simply joins the DAG as a leaf. In order words,  
> > the node has connectivity since it joins the DAG but will not act  
> > as a router for others since it does not understand the OF. Parent  
> > selection could be a simply a "random".

Now the question is whether or not RPL mandates the support of OF0.

Again two options:

1) We remove OF0 from the core spec. And nodes are free to implement  
the OF that they want

2) We do mandate for each node to support OF0

Pros/Cons:

If the support of OF0 in no longer mandatory, nodes operating in an  
environment requiring a specific OF just have to implement that OF.
On the other hand, when mixing nodes that do not support the same OF,  
they do not interoperate.

An alternative if we decide to make OF0 non mandatory is to indicate  
in some applicability statement the applications that would require  
the support of OF0.

Opinion ?

Thanks.

JP.