Subject: [sacm] IM Template Change Proposal

From: "Jim Schaad" <[email-masked]>
Date: Fri, 8 Apr 2016 11:11:07 -0300

After the discussions in the last F2F as well as some side bar meetings, I
have some proposals of possible changes to the current IPFIX template that
we are using.

1.  Delete the three container types in the current document.  (baseList,
subTemplateList, subTemplateMultiList)

2.  Define two new container types
	* List - unordered list of items
	* OrderedList - ordered list of items

3.  Define a new template field to hold the list definition for these new
types

4.  Define or modify the current list syntax to be, potentially, somewhat
richer.  I do not have a concrete proposal for this because I am not sure
what the set of properties that are needed here.  I believe that this list
includes one or more of the following:

*  The ability to have a set of properties
*  The ability to define a property as optional, required, repeatable, one
of a list of options.
*  There may be a requirement to be able to define sub-lists within the
syntax.  This is both a good thing to have and a potential problem.  If you
have something like  AddressSet ::= list( (addressType, ipv4Address |
ipv6Address | otherAddress) +) it is fine, but doing something like
AddressSet ::= (list (addressType, ipv4Address | ipv6Address),
list(macAddress, dnsAddress)) becomes a problem when trying to refer to the
elements as the lists are not themselves identified.  Sublists may not be
worth doing in order to have a name tag for each field.  It would be
possible however to basically create a syntax where the name is supplied and
the tree structure elements are implicitly created.  This makes descriptions
slightly easier.

The easiest syntax to use is probably a standard RE type syntax.

Jim