To solve this problem, we propose a new operation attribute for the
Send-Document (and, by extension, Send-URI) operations. Specifically, Integer
(1..MAX) "document-number" . This is a document sequence number that begins
with '1' for the first document, and is incremented by one for each subsequent
document up to and including the document with "last-document"='true'. Thus,
when the Printer|Job gets the final document (last-document=true), it can
examine the document-numbers of the documents previously received to a) ensure
that all have been received, b) determine the proper ordering of the documents
within the Job.
The "request-id" attribute doesn't quite solve this problem since there's no
guarantee that request-id numbers are ordered or contiguous.
This new operation attribute would be OPTIONAL, with the understanding that if
"document-number" is not supplied it's up to the IPP client to serialize the
requests by synchronously transmitting one document at a time.
IBM Printing Systems Co