Re: [Roll] [6lo] RPL artifact compression discussion

[Robert Cragie <[e-mail]>]

Hi Michael,

Comments inline.

Robert

On 23 March 2015 at 20:40, Michael Richardson <[e-mail]> wrote:

>
> 1) draft-thubert-6lo-rpl-nhc
>    originally proposal to add a new 6282 Next Header Compression for just
> 6553.
>    from that document:
>       (Discuss: Is this really an update of RFC 6282 or a straightforward
>        addition to it?)
>

<RCC>It's an extension as Carsten says.</RCC>


>    1b) NHC++ as noted below, there is no method defined to compress the
> IPv6
>
       inner header,


<RCC>There is - it's IPHC. You can use IPHC twice as we discussed in the
recent call.</RCC>

and no method to compress the RH3 (RFC6554) header
>        was defined.


<RCC>Yes - this is missing.</RCC>


> The NHC++ proposal suggests to expand this proposal to
>        do this.  It can perhaps be done in the greedy approach with
>        some thought, but it seems unlikely to fit, and the conservative
>        approach would be required.
>

<RCC>It is possible the efficient approach can be used as well as that
would be aimed mainly at RPI. Perhaps there is scope for applying the same
method to RH3.</RCC>

>
> 2) draft-thubert-6lo-routingdispatch
>
>    The NHC method above adds additional nexthops, but does not change
>    anything about the outer IPv6 header.  It would continue to be
> compressed
>    with 6282's LOWPAN_IPHC, and unfortunately, as there is no Next
>    Header=LOWPAN_IPHC,  the second (inner from the wild, likely more
> random),
>    header can not be compressed.
>

<RCC>It can, as shown in the recent call</RCC>