Capwap Mailing List: Issue 187: How to know the number of encryption sub-elements

[Pat Calhoun (pacalhou) (pcalhoun]

All,

Pasi brought up the following issue during the WG Last Call:

     Section 4.6.40: the bit diagram shows just one Encryption
Sub-Element.
     Also, how does the recipient figure out how many Encryption
Sub-Elements there are?

This is a very good point, and the message element needs to be modified
to include a
Field that represents the number of sub-elements.

<proposed text>
4.6.40.  WTP Descriptor

   The WTP Descriptor message element is used by a WTP to communicate
   its current hardware and software (firmware) configuration.  The
   value contains the following fields.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   Max Radios  | Radios in use |  Num Encrypt  |Encryp Sub-Elmt|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Encryption Sub-Element    |    Descriptor Sub-Element...
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Type:   39 for WTP Descriptor

   Length:   >= 31

   Max Radios:   An 8-bit value representing the number of radios (where
      each radio is identified via the Radio ID field) supported by the
      WTP.

   Radios in use:   An 8-bit value representing the number of radios in
      use in the WTP.

   Num Encrypt:   The number of 3 byte Encryption Sub-Elements that
      follow this field.  The value of the Num Encrypt field MUST be
      between one (1) and 255.

   Encryption Sub-Element:   The WTP Descriptor message element MUST
      contain at least one Encryption sub-element.  One sub-element is
      present for each binding supported by the WTP.  The Encryption
      sub-element has the following format:
</proposed text>

PatC