Subject: PNDN (draft-ietf-vpim-pndn-00.txt)

From: Eric Burger <[email-masked]>
Date: Fri, 20 Oct 2000 17:07:11 -0400

At 03:24 PM 9/4/00 +0900, Hiroshi Tamura wrote:
>[snip]
>To Eric:
>Some FAX WG people do not follow it well.
>Could you please explain PNDN briefly?

First of all, the URL for the draft is at
http://www.ietf.org/internet-drafts/draft-ietf-vpim-pndn-00.txt

PNDN, or Partial Non-Delivery Notification, is a NDN mechanism.

In the e-mail world, an e-mail either gets delivered in its entirety or not 
at all.

In the voice and fax worlds, or for that matter any situation where one 
sends a multiple-media message to a system that cannot render all the media 
types, parts of the message may not be delivered, even if the message was 
"delivered", in its entirety, to the receiving system.

PNDN reports on the delivery status of MIME body parts in a MIME 
message.  The message may be received successfully, but one or more 
"important" parts may not be renderable or even stored by the receiving 
system.  PNDN lets the sending system know about the status of the 
"important" parts.

Said differently, as RFC822 Message is to NDN, a MIME Body Part is to PNDN.

Such a mechanism may be of use to the ifax WG if you will be dealing with 
multiple-media messages, such as voice + fax being sent to a fax-only 
device.  It could also be useful if you send a multi-page fax as multiple 
MIME body parts.  In this case, if a page fails, the sender would get a 
report on the failed page, rather than failing the whole message.  However, 
PNDN would not be useful if there is only one body part, and a "sub-part", 
e.g., a page within a multi-page TIFF-F, fails.

If PNDN is of use to the ifax WG, I would be happy to resubmit it as a ifax 
WG draft, with any tweaks you may need.