Subject: [CCAMP] FW: draft-ietf-ccamp-general-constraint-encode

From: Leeyoung <[email-masked]>
Date: Fri, 25 Oct 2013 20:43:29 +0000

Here's some comments on draft-ietf-ccamp-general-constraint-encode from Ramon and the resolution. 

Thanks,
Young

-----Original Message-----
From: Leeyoung [mailto:[email-masked]] 
Sent: Friday, October 25, 2013 3:19 PM
To: Ramon Casellas; [email-masked]
Cc: Morro Roberto
Subject: RE: draft-ietf-ccamp-general-constraint-encode

Hi Ramon,

It works for me. Please confirm the changes: 

s/PRI (Priority Flags, 8 bits): Indicates priority level applied to
     Label Set Field. Bit 8 corresponds to priority level 0 and bit 15
     corresponds to priority level 7

/PRI (Priority Flags, 8 bits): A bitmap used to indicate which priorities
       are being advertised.  The bitmap is in ascending order, with the
       leftmost bit representing priority level 0 (i.e., the highest) and
       the rightmost bit representing priority level 7 (i.e., the
       lowest).  A bit MUST be set (1) corresponding to each priority
       represented in the sub-TLV, and MUST NOT be set (0) when the
       corresponding priority is not represented.  At least one priority
       level MUST be advertised that, unless overridden by local policy,
       SHALL be at priority level 0.

And Appendix A.5 will be changed as follows: 

A.5. Priority Flags in Available/Shared Backup Labels sub-TLV

   If one wants to make a set of labels (indicated by Label Set Field
   #1) available only for highest priority level (Priority Level 0)
   while allowing a set of labels (indicated by Label Set Field #2)
   available to all priority levels (Priority Level 7), the following
   encoding will express such need.

      0                   1                   2                   3
      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 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 0 0 0|              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field #1                        |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 1 1 1 1 1 1 1|              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field #2                        |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

-----Original Message-----
From: Ramon Casellas [mailto:[email-masked]]
Sent: Friday, October 25, 2013 3:00 PM
To: Leeyoung; [email-masked]
Cc: Morro Roberto
Subject: Re: draft-ietf-ccamp-general-constraint-encode

El 25/10/2013 21:26, Ramon Casellas escribió:
> El 25/10/2013 21:24, Leeyoung escribió:
>> Hi Ramon,
>>
>> If I recall, the pri field was 3 bits and someone (I forgot) raised 
>> that it should be a 8-bit field to match with other priority encoding 
>> in MPLS.

Hi again, my hopeful final message :-) but it is slightly different (the good part, it does not change the size and it goes in line with OTN)

I checked, for example,
http://tools.ietf.org/html/draft-ietf-ccamp-gmpls-ospf-g709v3-10
which is much clearer:

- I has 8 bits field, each bit corresponding to a priority
- Bits are set to "1" is that priority "applies".
- The same labelset can be used for different priorities, without copying each one
- So it would leave a 8 bit field

      - Priority (8 bits): A bitmap used to indicate which priorities
       are being advertised.  The bitmap is in ascending order, with the
       leftmost bit representing priority level 0 (i.e., the highest) and
       the rightmost bit representing priority level 7 (i.e., the
       lowest).  A bit MUST be set (1) corresponding to each priority
       represented in the sub-TLV, and MUST NOT be set (0) when the
       corresponding priority is not represented.  At least one priority
       level MUST be advertised that, unless overridden by local policy,
       SHALL be at priority level 0.

I guess the final message is "we should change something, not sure what" :) R.

--
Ramon Casellas, Ph.D. -- Senior Research Associate -- Networks Division Optical Networks and Systems Department -- http://wikiona.cttc.es CTTC - Centre Tecnològic de Telecomunicacions de Catalunya Parc Mediterrani de la Tecnologia (PMT) - Edifici B4 Av. Carl Friedrich Gauss, 7 - 08860 Castelldefels (Barcelona) - Spain
Tel.: +34 93 645 29 00 ext 2168-- Fax. +34 93 645 29 01