Subject: [ANCP] Unsupported registry in ANCP base protocol document

From: Tom Taylor <[email-masked]>
Date: Sun, 14 Feb 2010 22:05:28 -0500

The ANCP Command Code registry in the base protocol document is in the awkward 
position of reserving a value for a field that is not defined in that document. 
May I suggest that we provide the necessary support by carving the Command Code 
field out of the existing Command Info field, so that the latter starts with the 
second byte of the second word of the TLV? The result would look like this:

   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
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |     TLV Type = Command        |       Command-TLV Length      |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |  Command Code |                                               |
  +-+-+-+-+-+-+-+-+                                               +
  ~                         Command Info                          ~
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |     Additional sub-TLV Type   |   Additional sub-TLV Length   |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                                                               |
  ~                   Additional sub-TLV data                     ~
  |                                                               |
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The descriptive text would add that extensions to ANCP MAY add new values for 
the Command Code field.

Tom