Re: [6tisch] Benjamin Kaduk's Discuss on draft-ietf-6tisch-architecture-24: (with DISCUSS and COMMENT)

["Pascal Thubert (pthubert)" <[e-mail]>]

Great!

We asked for that change at the time, and clearly it was implemented.
This means that the text in the Architecture is now obsolete and I’ll remove it.

Many thanks Tero.

Pascal

> Le 8 août 2019 à 23:58, Tero Kivinen <[e-mail]> a écrit :
> 
> Benjamin Kaduk via Datatracker writes:
>> ----------------------------------------------------------------------
>> DISCUSS:
>> ----------------------------------------------------------------------
>> 
>> Section 4.3.4 asserts:
>> 
>>   [...]                                      We'll note that the Join
>>   Priority is now specified between 0 and 0x3F leaving 2 bits in the
>>   octet unused in the IEEE Std. 802.15.4e specification.  After
>>   consultation with IEEE authors, it was asserted that 6TiSCH can make
>>   a full use of the octet to carry an integer value up to 0xFF.
>> 
>> I'm extremely reluctant to publish this text in the IETF stream without
>> a citation.
> 
> IEEE Std 802.15.4-2015 says:
> 
> ----------------------------------------------------------------------
> 7.4.4.2 TSCH Synchronization IE
> 
> The TSCH Synchronization IE Content field shall be formatted as
> illustrated in Figure 7-50.
> 
>          +-------------+---------------+
>      |  Octets: 5  |       1       |
>          +-------------+---------------+
>      |     ASN     |  Join Metric  |
>          +-------------+---------------+
> 
>     Figure 7-50 -- TSCH Synchronization IE Content field format
>       
> The ASN field contains the ASN corresponding to the timeslot in which
> the enhanced beacon is sent. The ASN is used as the Frame Counter for
> security operations if enabled.
> 
> The Join Metric field is an unsigned integer and shall be set to
> macJoinMetric.
> ----------------------------------------------------------------------
> 
> And
> 
> ----------------------------------------------------------------------
> 
> Section 8.4.2.2 TSCH-specific MAC PIB attributes
> 
> ...
> 
>       Table 8-83 -- TSCH-specific MAC PIB attributes
> 
> Attribute    Type     Range       Description                     Default
> ...
> macJoinMetric    Integer     0x00–0xff   The sum of one and the         1
>                     value of the Join Metric
>                     field from the TSCH
>                     Synchronization IE, 7.4.4.2,
>                     received in the Enhanced Beacon
>                     frame used by the device
>                     joining the network. If the
>                     device is the an endpoint, the
>                     value shall be set to zero.
> 
> ----------------------------------------------------------------------
> 
> So it is very clear that Join Metric can be any number between
> 0x00-0xff. 
> 
>>   scheduled cell:  A cell which is assigned a neighbor MAC address
>>               (broadcast address is also possible), and one or more of
>>               the following flags: TX, RX, shared, timeskeeping.  A
>> 
>> "timeskeeping" does not seem to be defined anywhere.
> 
> Timekeeping comes from the IEEE Std 802.15.4-2015 Section 7.4.4.3 TSCH
> Slotframe and Link IE:
> 
> ----------------------------------------------------------------------
>   The Timekeeping field shall be set to one if the link is to be used
>   for clock synchronization and shall be set to zero otherwise. RX
>   links shall have the Timekeeping field set to one.
> -- 
> [e-mail]