Re: [IPFIX] unobserved fields

[Paul Aitken <[e-mail]>]

Andrew,

> My earlier email about Extended Field Specifiers reminded me of an 
> other draft (draft-aitken-ipfix-unobserved-fields) that doesn't seem 
> to have gone anywhere, but that I would love to move forward. Having a 
> standard way to know if  field is unobserved/NULL for a given flow 
> would be very valuable.

It's not that this draft didn't go anywhere. Rather, I've written all I 
can for now, yet the WG isn't in a position to adopt the work. However 
it's a real issue that needs to be solved -in fact, we're already using 
some of the techniques in this document - so in my mind it's only "on 
hold" until I think of something to add and/or the WG can adopt it.

You're right, Extended Field Specifiers would allow us to tag each field 
with an "Observed" attribute with advantages:

     - we wouldn't need to change fields to varlen just to report length 
= 0.

     - we could have a many-valued reason rather than a boolean.
         ie, we can report why the value is not available or not applicable.

P.