[Roll] Unaware-leaves - ND-Status and RPL-Status linkage

[Rahul Jadhav <[e-mail]>]

Hello Pascal, Michael, All,

I would like to open the discussion about carrying the ND Status as
part of the RPL Status as mentioned in the Unaware-leaves draft [1].

The proposition by Unaware-leaves draft wrt RPL status is:
Use of RPL status to carry ND status. ND Status (RFC 8505) is 8bits,
and RPL status is 8bits. RPL status MSB is already used to indicate
outright rejection. Unaware-leaves draft dedicates 2nd MSB in RPL
status to indicate ND status. This means only lower 6-bits of ND
Status can be at most carried in RPL status.

The RPL Status carrying ND Status seems not adequate,
1) RPL Status can carry only lower 6bits of the 8bits of ND Status
2) RPL Status and ND Status may not always be correlated.

How about using a different ND Option in RPL messaging to keep the ND
handling segregated? The unaware draft can say that this option can be
carried in DCO or any other RPL message it requires. ND status/option
may have to be carried only in specific cases which involves unaware
leaves and as such the control overhead due to option header may not
be much.

This ND option could also be easily extended for future purposes since
we may have additional fields in the future from ND to be carried with
RPL.

Regards,
Rahul

[1] https://tools.ietf.org/html/draft-ietf-roll-unaware-leaves-07