Re: [6lowpan] "Advertize on Behalf" flag in ARO

[Erik Nordmark <[e-mail]>]

On 3/30/11 1:30 AM, Pascal Thubert (pthubert) wrote:
> Hi Carsten:
>
> RPL recognizes a movement when a DAO information has a stale
> DAOSequence. The DAOSequence is an information that the owner of the
> advertised target increments.
> If we define an interaction whereby we redistribute ND-15 into RPL, then
> (probably) the RPL router will inject a host route on behalf of the
> host.
> When the RPL router injects such a route and then maintains that route,
> it still has has to provide an idea of the freshness of the information
> that it is injecting in a DAOSequence.
> When the host moves to an alternate router, it would have to provide
> something so that the new router sets an updated DAOSequence that the
> routing update percolates up the DODAG.
> IOW, without a TID, a host cannot efficiently move from a router to the
> next.

Why couldn't the RPL router take a timestamp when it hears an ARO from a 
host, and convey that in RPL? Then that timestamp can be used to 
determine the most recent registration i.e., determine the most likely 
topological location of the host.

The beauty of such an approach is that it avoids requiring having the 
hosts know about routing protocol-specific information like a TID.

    Erik