This question is related to
draft-maeda-faxwg-fax-processing-status-00.txt.
A long time ago, I recall that some ifax sending devices would (or
could) send a multiple pages as multiple one-page TIFF
attachments.
Here is a description of several different valid messages which describe
the problem I see with the current proposal in
draft-maeda-faxwg-fax-processing-status-00.txt. The problem is that it
cannot identify the "page" successfully -- the definition of a page is
different from the sender and the receiver's view. Email allows
much richer operation than scanning, transmitting, and printing. This
richer operation means a straight-forward "page NNN failed" is not
sufficient for email.
A proposal to resolve this problem is below. The proposal allows
operation as described in draft-maeda-faxwg-fax-processing-status-00.txt
while also allowing the richer operation of email.
Method 1:
From: someone@xxxxxxxxxxx
To: someone-else@xxxxxxxxxxx
Subject: 3 page fax
Message-ID: <123@xxxxxxxxxxx>
Date: 1 Jan 2001 01:00:00 -0800
Content-Type: multipart/mixed; boundary=ABC
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC--
Method 2:
From: someone@xxxxxxxxxxx
To: someone-else@xxxxxxxxxxx
Subject: 3 page fax
Message-ID: <123@xxxxxxxxxxx>
Date: 1 Jan 2001 01:00:00 -0800
Content-Type: multipart/mixed; boundary=ABC
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC--
Method 3:
From: someone@xxxxxxxxxxx
To: someone-else@xxxxxxxxxxx
Subject: 3 page fax
Message-ID: <123@xxxxxxxxxxx>
Date: 1 Jan 2001 01:00:00 -0800
Content-Type: multipart/mixed; boundary=ABC
--ABC
Content-type: text/plain
FAX COVERSHEET
From: Jim
To: Susan
Date: 1 Jan 2001 01:00:00, Pacific Time
Contact: jim@xxxxxxxxxxx, 408-555-1212
Susan,
Here is the fax you requested. There should be 4 pages total
(this coversheet, plus 3 pages of the fax content itself).
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC--
To support non-ASCII languages on the coversheet, the first part in Method
3 could be image/tiff which contains a graphical representation of the
coversheet.
Method 4:
From: someone@xxxxxxxxxxx
To: someone-else@xxxxxxxxxxx
Subject: 3 page fax
Message-ID: <123@xxxxxxxxxxx>
Date: 1 Jan 2001 01:00:00 -0800
Content-Type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
Method 5:
From: someone@xxxxxxxxxxx
To: someone-else@xxxxxxxxxxx
Subject: your two faxes: Sumerset, Egghead
Content-Type: multipart/mixed; boundary=ABC
Date: 1 Jan 2001 01:00:00 -0800
Message-ID: <123@xxxxxxxxxxx>
--ABC
Content-type: text/plain
FAX COVERSHEET
From: Jim
To: Susan
Date: 1 Jan 2001 01:00:00, Pacific Time
Contact: jim@xxxxxxxxxxx, 408-555-1212
Susan,
Here are your two faxes. The first one is a 3 page fax from
Sumerset, Inc. The second one is a 9 page fax from Egghead.
Thanks.
Jim
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC
content-type: image/tiff
content-transfer-encoding: base64
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
EJKFJFKEJKEFJFKJEFJKEJFEJFKEJ
--ABC--
I _believe_ that most dedicated ifax devices use Method 4, above. I
believe most of the typical mailers (Netscape, Eudora, Outlook) would use
Method 2 or Method 3, above.
I feel it is critical that any MDN or DSN response indicating a portion of
a message was successfully or unsuccessfully processed must also indicate
which MIME part is being described in the MDN or DSN reponse -- it is NOT
as simple as the "page" having the problem, especially if Method 1 is used
-- they are all page "1" from the view of the sender. Method 1 is a valid
message format and is allowed, so we must handle it correctly.
I propose we require the use of Content-ID to identify MIME parts. This
identification allows the MDN to indicate which part(s) were successfully
or unsuccessfully processed.
Content-ID is described in RFC2045, section 7. Its use is discussed in
RFC2046.
-Dan Wing