[6lo] Comments of draft-jadhav-lwig-nbr-mgmt-policy-00

[Zhen Cao <[e-mail]>]

Dear Rahul and co-authors,

Many thanks for the hard work in contributing this draft to the lwig
wg. (I am copying roll and 6lo since some discussion will be quite
relevant)

As I go through the document, I found essentially there are three
types of different policies discussed:
a. Trivial neighbor management (FCFS/LRU)
b. advanced neighbor management (proactive and reactive)
c. proposed ‘reservation based’ approach

Logically I understand the shortcomings of the trivial approach,
however in practice, how much this many impact the network stability
is not convincing enough yet. (what’s the possible size of node
density/mobility may be impacted? ).

The discussion of reactive and proactive ways of managing the neighbor
cache entries is helpful. The discussion about the proactive approach
in Sec.2.5.2 quoted below has some pending relationship with RPL (if
this is an acknowledged problem by ROLL WG).  Anyway this is something
we need to discuss with the ROLL wg to see if this a need feature.

    Currently there is no standard way of signaling such neighbor cache
   space availability information.  RPL's DIO messages carry metric
   information and can be augmented with neighbor cache space as an
   additional metric.

For the proposed reservation based approach,  I think this is quite a
practical recommendation (if my concern about a. will be relaxed).

I also found the Contiki RPL implementation has recently used a
similar way in its rpl-nbr-policy. Shall we link the draft to the open
source community to see if the document has provided additional help
to the implementation? (or that’s already done given coauthors Simon
and Joakim are both active contributors of Contiki)?

Many thanks for discussion.

Cheers,
Zhen