Subject: Re: [Roll] [roll] #46: Comment on METRIC-ID

From: "roll issue tracker" <[email-masked]>
Date: Fri, 11 Jun 2010 11:42:58 -0000

#46: Comment on METRIC-ID
--------------------------------+-------------------------------------------
 Reporter:  jpv@…               |        Owner:  jpv@…        
     Type:  defect              |       Status:  closed       
 Priority:  major               |    Milestone:               
Component:  routing-metrics     |      Version:               
 Severity:  Active WG Document  |   Resolution:  fixed        
 Keywords:                      |  
--------------------------------+-------------------------------------------
Changes (by jpv@…):

  * status:  new => closed
  * resolution:  => fixed

Comment:

 Fixed:

 4.4.1.  Link Color Object Description

    The Link Color (LC) object is an administrative 10-bit static link
    constraint used to avoid or attract specific links for specific
    traffic types.

    The LC object can either be used as a metric or as a constraint.
    When used as a metric, the LC metric can only be recorded.  For
    example, the DAG may require recording the link colors for all
    traversed links.  Each node can then use the LC to select the parent
    based on user defined rules (e.g. "select the path with the maximum
    number of links having their first bit set 1 (e.g. encrypted
    links)").  The LC object may also be used as a constraint.

 Vasseur, et al.         Expires December 12, 2010              [Page 20]

 Internet-Draft     draft-ietf-roll-routing-metrics-07          June 2010

    When used as a recorded metric, a counter is used to compress the
    information where the number of links for each Link Color is
    reported.

    The Link Color (LC) object MAY be present in the DAG Metric
    Container.  There MUST be only one LC object with at least one LC
    sub-object per DAG Metric Container object.

    The LC routing object does not contain any additional TLV.

    The LC routing object Type is to be assigned by IANA (recommended
    value=8)

    The LC object may either be local or global.

    The format of the LC object body is as follows:

      0               1               2
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...
     |      Res      | LC Sub-objects
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ...

       Figure 16: LC Object format

    When the LC object is used as a global recorded metric, the LC object
    body comprises one or more LC Type 1 sub-objects.

    The format of the LC Type 1 sub-object body is as follows:

     0               1
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |    Link Color     |  Counter  |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 17: LC Type 1 sub-object format

    When the LC object is used as a constraint, the LC object body
    comprises one or more LC Type 2 sub-objects.

 Vasseur, et al.         Expires December 12, 2010              [Page 21]

 Internet-Draft     draft-ietf-roll-routing-metrics-07          June 2010

    The format of the LC Type 2 sub-object body is as follows:

     0               1
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |           Link Color        |I|
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Figure 18: LC Type 2 sub-object format

    I Bit: When cleared, this indicates that links with the specified
    color must be included.  When set, this indicates that links with the
    specified color must be excluded.

    The use of the LC object is outside of the scope of this document.

-- 
Ticket URL: <https://svn.tools.ietf.org/wg/roll/trac/ticket/46#comment:1>
roll <http://tools.ietf.org/wg/roll/>

---

From: JP Vasseur <[email-masked]>
Date: Fri, 11 Jun 2010 13:45:38 +0200

Good points. Res fields augmented by 4 bits for octets alignments.
This is in revision 07.

Thanks.

JP.

Begin forwarded message:

> From: "roll issue tracker" <[email-masked]>
> Date: June 5, 2010 12:51:07 PM CEDT
> To: [email-masked]
> Cc: [email-masked]
> Subject: [roll] #46: Comment on METRIC-ID
> Reply-To: [email-masked]
>
> -------------------------------- 
> +-------------------------------------------
>     Type:  defect              |      Status:  new
> Severity:  Active WG Document  |    Keywords:
> -------------------------------- 
> +-------------------------------------------
> Mads Westergreen
>
>
> 7.       RPL metrics draft 06  - 4.3.1.  The Link Quality Level
> Reliability Metric
>                                             4.4.1.  Link Color Object
> Description
> Both these options have the first 4 bits reserved. The length of the
> option following these 4 bits is multiple of 8 bits. It would make  
> more
> sense if the reserved bits are extended to 8 because:
> a)      The information following them will be easier to read/write,  
> as it
> will start on memory boundaries. Now it has to be shifted.
> b)  The frame will be anyway have to be completed with 4 trailing bits
> after the option
>                     Any reason why the reserved bits cannot be  
> extended to
> 8 ?
>
> -- 
> Ticket URL: <https://svn.tools.ietf.org/wg/roll/trac/ticket/46>