Xavi - please see my responses inline

> On Dec 12, 2016, at 11:35 PM, Xavi Vilajosana Guillen <[email protected]> 
> wrote:
> 
> Dear Jonathan,
> 
> thanks for your comments. See inline our responses:
> 
> 2016-12-12 22:48 GMT+01:00 Jonathan Simon <[email protected] 
> <mailto:[email protected]>>:
> Xavi, Kris - Some questions about draft 17:
> 
> 4: The callouts in figure 1 don't exactly match what's in 4.5.2, namely that 
> the timelsot and hopping template IDs (as opposed to the full sequence) are 
> what is carried in the EB.
> 
> XV: The proposed configuration as advertised in the EB uses the default 
> timeslot and hopping template ID. macTimeslotTemplateId = 0 and the default 
> (macHoppingSequenceID = 0). Following your suggestion I will change the table 
> to indicate this (macHoppingSequenceID = 0). Should we also keep the default 
> sequence as a clarification (indicating that) [5, 6, 12, 7, 15, 4, 14, 11, 8, 
> 0,  1, 2, 13, 3,  9, 10]?

JS - I don't think you need to call out the specific sequence. It should be 
sufficient to cite 802.14.5 section 6.2.10 which describes how it is generated.
>  
> 4.5: This paragraph could be interpreted as saying that a compliant node may 
> choose particular settings, but must be able to understand all possible valid 
> TSCH settings to be 6TiSCH compliant.  I don't understand that you "may" set 
> to any valid TSCH setting but you "should" set them to what is specified 
> later on.  
> 
> 
>  
> XV: You are right. We need to clarify this. I think we want to be clear here 
> with the recommended frame format. I try to rephrase it. 

JS - thanks!
> 
>  
> 4.5.1:  
> 1) What is the EB source address size?   Presumably the dst is short FFFF, 
> but it isn't stated. 
> 
> XV: According to 15.4 -2015
> page 65.
> 
> "The Source Address field, if present, shall contain the address of the 
> device sending the frame. When a
> device has associated and has been allocated a short address (i.e., 
> macShortAddress is not equal to 0xfffe or
> 0xffff), it shall use that address in preference to its extended address 
> (i.e., macExtendedAddress) wherever
> possible. When a device has not yet associated to a PAN, it shall use its 
> extended address in all
> communications requiring the Source Address field. If the Source Address 
> field is not present, the originator
> of the frame shall be assumed to be the PAN coordinator or RFD-TX device, and 
> the Destination Address
> field shall contain the address of the recipient, optional for RFD-TX 
> devices."
> 
> The destination address should be 0xFFFF as you indicate. (short address). 
> The source should be the node's extended address as per table 7-6 of 
> 15.4-2015 (page 117) (12th row of the table). 

JS - I would think that if the JA beaconing has a short address, whether we use 
the association process discussed in 15.4 section  6.4.1 or not, then it should 
beacon using its short address (table 7-6 line 13), unless this makes it 
impossible for the JN to properly address its join request.   

In either case, I think an explicit callout to the address size in the text 
would be helpful. 
>  
> 2)  "While listening for EBs, a joining node set its own PAN ID to 0xffff..." 
> Why is the PAN ID set to FFFF? This implies that the EB either doesn't have a 
> dst PAN ID (contrary to the previous paragraph) or that nodes accept EB's 
> from any advertising PAN, which makes PANID not useful in partitioning 
> networks. 
> 
> XV: This comes from some discussions we had some time back. I will try to 
> find the threads. As far as I remember, the concern was that the PAN ID is 
> not known by the node performing the scan. Then in order to be able to accept 
> the EB following the filtering rules (level 3) defined in the 15.4-2011. 
> section 5.1.6.2 or later in section 6.7.2 of 15.4-2015 the PAN ID has to be 
> set to FFFF.  I agree with you that we need to check this again.

JS - to me this is policy.  If I as a vendor want to partition networks by 
PANID, then I can do so, and if I want to be able to join any PAN, I can do so. 
 I think a statement that setting to FFFF allows the JN to join any PAN is 
sufficient.
> 
> 
> 4.5.2:  "EBs SHOULD NOT be used for time synchronization." The JN must 
> initially set it's clock from the EB, otherwise it will have no idea when to 
> send in its join request - see 6.2.   I think you mean that EB's should not 
> be used for time synchronization after a node has K2?
> 
> XV: I agree. We need first to join the network. I will correct that. 

JS - thanks
> 
> 4.6: How do you send in a join request using K2 (since it is a data frame and 
> not an EB) when you don't have K2 yet?
> 
> XV: Good point. we do not say how K2 is provisioned. This is something that 
> other documents in the WG should specify. In case K2 is pre-provisioned this 
> is solved, however, the zero or one touch approaches should clarify this I 
> guess. Do you have any suggestion for that? I understand that considering 
> only minimal, if K2 is not pre-provisioned, we cannot join the network unless 
> we use another mechanism.

JS - I think you've hit on the point - frames should be secured with K2 once K2 
is provisioned.  Then you can say that can be done a priori, or refer to 
Mališa's minimal security draft (or Michael's draft) as an example of how K2 
get's provisioned. 


> 
>  
> Jonathan
> 
> [email protected] <mailto:[email protected]>
> 
> 
> 
> 
> -- 
> Dr. Xavier Vilajosana Guillén­
> Research Professor
> Wireless Networks Research Group
> Internet Interdisciplinary Institute (IN3)
> Universitat Oberta de Catalunya­
>  
> +34 646 633 681| [email protected] <mailto:[email protected]>­ | Skype­: 
> xvilajosana
> http://xvilajosana.org 
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> 

Jonathan Simon
[email protected] <mailto:[email protected]>


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