Subject: [CCAMP] questions regarding [gen-encode] draft

From: Annapoorni Neelankantan <[email-masked]>
Date: Mon, 22 Apr 2013 12:49:04 +0000

Hello Authors,

I have few questions regarding the [gen-encode draft] - "draft-ietf-ccamp-general-constraint-encode-10.txt

The mentioned draft has expired on 28 march 2013. But all the WSON specific documents refer to this document for reference.

Is the "draft-ietf-ccamp-general-constraint-encode-10.txt still valid??

Questions pertaining to "draft-ietf-ccamp-general-constraint-encode-10.txt"

1)      In Section 2.3.Available Labels Sub-TLV defines priority as 8 bits.
However in the example
      A.5. Priority Flags in Available/Shared Backup Labels sub-TLV
                Priority is defined as 3 bits.
Since there is a mismatch, How many bits should be used to represent priority?

2)      In the same example A.5 Priority Flags in Available/Shared Backup Labels sub-TLV,
                7 mentioned as the highest priority. In ASON/Packet world, "0" is the highest priority and "7" the lowest.
                Could you please comment as to whether 0 or 7 constitutes highest priority ?

3)      In section 2.3<http://tools.ietf.org/html/draft-ietf-ccamp-general-constraint-encode-10#section-2.3>. Available Labels Sub-TLV

   The Available Labels sub-TLV link consists of an availability flag,

   priority flags, and a single variable length label set field as

   follows:

      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

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |     PRI       |              Reserved                         |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |                     Label Set Field                           |

     :                                                               :

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where

   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.

     a)  What is the use/definition of availability flag ?
     b) Where should  priority be  encoded, in the first byte(0-7bits) or (8-15bits)? Diagram show the first byte whereas the
       explanation says it as the second byte.

4)      In "Available Labels Sub-TLV", assuming Priority is defined by 8 Bits -

If two bits are set to indicate that available labels for 2 priorities, should the available labels at each priority be encoded as below?

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | 01000001  |              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field for priority = 1          |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field for priority = 7          |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

5)      In the "Label Set" field of Available Label set TLV,  what does "Lowest Frequency" signify?

Is it the lowest frequency supported by the port for a particular grid and channel spacing ?

OR

Is it the lowest available frequency i.e the lowest frequency which is not in use, at that point in time?

                In Example A.2 in the draft,
                For the following frequencies which are available (and not in use)
      Frequency (THz)       n Value      bit map position
     --------------------------------------------------
      192.0             -11                  0
      192.5              -6                  5
      193.1               0                 11
      193.9               8                 19
      194.0               9                 20
      195.2              21                 32
      195.8              27                 38
      Encoding is:
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  4    | Num Wavelengths = 40  |    Length = 16 bytes          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = -11 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 0 1 0|   Not used in 40 Channel system (all zeros)   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                If the available frequencies are:
      Frequency (THz)       n Value      bit map position
     --------------------------------------------------
      193.9               8                 19
      194.0               9                 20
      195.2              21                 32
      195.8              27                 38

      Will the value of "n" change in the encoding change to "8", OR will it still remain "-11" ?
      Will the Encoding change as below:
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  4    | Num Wavelengths = 40  |    Length = 16 bytes          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = 8 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 0 1 0|   Not used in 40 Channel system (all zeros)   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Thanks
Annapoorni

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