Subject: [Roll] Selecting from multiple DODAGs

From: "JeongGil Ko (John)" <[email-masked]>
Date: Thu, 18 Feb 2010 20:08:01 -0800

Hi!

Thanks Jonathan for the previous clarification :) I have another question that came up during the implementation process. When a RPL node selects a DODAG between multiple DODAGs, the draft specifies that the RPL node should select the DODAG that has higher preference or a DODAG that advertises OFs that the RPL node understands. However, consider the case where there are two DODAGs with the same preference and both advertising OFs that the RPL node understands. In such case, is it correct to assume that the node will select 'any' DODAG to connect to (e.g., the DODAG that will result in a lower rank)? Or is there another criteria in the DODAG selection process that I am missing?

Thanks!

-John

------
JeongGil Ko (John)
Ph.D. Student
Department of Computer Science
Johns Hopkins University
http://www.cs.jhu.edu/~jgko

---

From: Jonathan Hui <[email-masked]>
Date: Fri, 19 Feb 2010 00:09:55 -0800

Hi John,

All things being equal, a node that must choose between different  
DODAGs can choose whatever DODAG it likes.  Of course, other things  
can affect what DODAG a node joins (e.g. grounded vs. not grounded,  
same OFs advertising different metric values, any dwell timing used  
when jumping between different DODAGs, etc.), some of which may be  
implementation dependent.

--
Jonathan Hui

On Feb 18, 2010, at 8:08 PM, JeongGil Ko (John) wrote:

> Hi!
>
> Thanks Jonathan for the previous clarification :) I have another  
> question that came up during the implementation process. When a RPL  
> node selects a DODAG between multiple DODAGs, the draft specifies  
> that the RPL node should select the DODAG that has higher preference  
> or a DODAG that advertises OFs that the RPL node understands.  
> However, consider the case where there are two DODAGs with the same  
> preference and both advertising OFs that the RPL node understands.  
> In such case, is it correct to assume that the node will select  
> 'any' DODAG to connect to (e.g., the DODAG that will result in a  
> lower rank)? Or is there another criteria in the DODAG selection  
> process that I am missing?
>
> Thanks!
>
> -John
>
> ------
> JeongGil Ko (John)
> Ph.D. Student
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> Roll mailing list
> [email-masked]
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