Re: [icnrg] ICNLoWPAN Document Action

[Cenk Gündoğan <[e-mail]>]

Dear group,

I was in contact with the designated expert (Pascal Thubert) for the
6lowpan dispatch registry.  Pascal asked whether we could optimize the
dispatch allocation space.  I had to juggle with a few bits; all minor
changes.

For CCNx, we formerly compressed the "Version" field and used a "bit"
for denoting that.  In the current diff, this "version bit" is missing
now to gain space and we always assume CCNx version 1 (as mandated by
CCNx [1]).  This is also what 6LoWPAN is doing with the IP version
field.

The current diff is here [2].  There aren't any major changes since my
last request for feedback.  So any feedback by next monday is welcome
before we move forward?

Thanks,
Cenk

[1] https://datatracker.ietf.org/doc/html/rfc8609#section-3.2
[2] https://tools.ietf.org//rfcdiff?url1=draft-irtf-icnrg-icnlowpan-10&url2=https://inet.haw-hamburg.de/tmp/draft-irtf-icnrg-icnlowpan-11.txt/@@download/file/draft-irtf-icnrg-icnlowpan-11.txt

On Wed, Sep 22 2021 at 19:03 +0200, Cenk Gündoğan wrote:

> [[PGP Signed Part:Undecided]]
> Dear group,
>
> just a heads-up that we will proceed with the below proposed solution to
> fix the mentioned registry clashes.
>
> Thanks,
> Cenk
>
> On Wed, Sep 15 2021 at 08:26 +0200, Cenk Gündoğan wrote:
>
>> [[PGP Signed Part:Undecided]]
>> Dear group,
>>
>> Table 2 of the ICNLoWPAN document [1] requests IANA updates to the
>> "6LoWPAN Dispatch Type Field" registry.  The last entry of table 2
>> clashes, however, with an existing registration. (11 11xxxx for "Page
>> dispatch").
>>
>> The solution is simple: we increase the prefix for the last entry from
>> "11 1xxxxx" to "11 10xxxx".  This decreases the option space for
>> dispatches, but that particular dispatch (Figure 26) has a "Reserved"
>> bit, which we can drop to increase it again.
>>
>> This:
>>  0                                       1
>>  0   1   2   3   4   5   6   7   8   9   0   1   2   3   4   5	 	  
>> +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+	  
>> | 1 | 1 | 1 |CID|EXT|VER|FLG|FRS|PAY|RCT|MGH| PLTYP |EXP|VAL|RSV|	  
>> +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+	  
>>   	
>> Becomes:
>> 0                                       1
>> 0   1   2   3   4   5   6   7   8   9   0   1   2   3   4   5	        
>> +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+	
>> | 1 | 1 | 1 | 0 |VER|FLG|FRS|PAY|RCT|MGH| PLTYP |EXP|VAL|CID|EXT|	
>> +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+	
>>
>> This diff [2] summarizes the necessary changes, it also moves the CID
>> and EXT bits of all dispatches to the end to keep the styling
>> harmonized.
>>
>> What does the group think about this proposed solution?  Are there any
>> objections?  To let it sufficiently marinate, feedback is very welcome
>> until wednesday next week :-)
>>
>> Cheers,
>> Cenk
>>
>> [1] https://datatracker.ietf.org/doc/html/draft-irtf-icnrg-icnlowpan-10
>> [2]
>> https://tools.ietf.org//rfcdiff?url1=draft-irtf-icnrg-icnlowpan-10&url2=https://inet.haw-hamburg.de/tmp/draft-irtf-icnrg-icnlowpan-11.txt/@@download/file/draft-irtf-icnrg-icnlowpan-11.txt