The June 2000 version of the Notification spec had the following statements
as part of the "notify-persistence" Subscription Template attribute (which
allowed the client to request persistence or not):
It is RECOMMENDED that all Subscription Objects be persistent. If Jobs are
persistent, the Per-Job Subscription Objects MUST be persistent too.
We agreed to delete this Subscription Template attribute and the statement
was deleted as well.
Should we add the above statement back into the Notification Spec?
Since the RFC 2911 doesn't appear to recommend persistent jobs, but does
admit to an implementation having persistent jobs, how about just adding the
second sentence to the Notification Spec:
If Jobs are persistent, i.e., are preserved across power cycles, then
Per-Job Subscription Objects MUST be persistent too.
Adding such a statement is what Ira is suggesting as well.
Also the statement that Harry excerpted from the
"notify-lease-expiration-time" attribute description could be
When the Printer powers up, it MUST set the value of this attribute in each
persistent Subscription Object using the algorithm in the previous
Harry correctly interpreted the adjective "persistent" meaning any
Subscription object that MAY be persistent rather than meaning that all
Subscription objects are persistent (by definition).
It might help to clarify that sentence by replacing it with the following
If a Printer has persistent Subscription object when it powers up, it MUST
set the value of this attribute in each persistent Subscription Object using
the algorithm in the previous paragraph.
From: McDonald, Ira [mailto:IMcDonald@crt.xerox.com]
Sent: Wednesday, August 29, 2001 09:13
To: 'Harry Lewis'; firstname.lastname@example.org
Subject: RE: IPP> Notification Subscriptions across Power Cycles
Concensus on more recent IPP Fax telecons this summer has been that
Subscription objects themselves MUST have the same lifetime as
their associated Jobs. And further that BOTH the Subscription and
the Job (with _all_ of its attributes) MUST persist until the
lifetime of the 'job-completed' event (last event) has expired.
So, I suggest that:
If an IPP Printer supports "persistent" Jobs (across power cycles),
then that IPP Printer MUST support "persistent" associated per-job
Now, if event lifetimes are long enough, do the actual _events_
"persist" into the next power cycle, if necessary (according to
the event delivery method constraints in 'notify-recipient-uri')?
- Ira McDonald
High North Inc
Does IPP have a "position" on either per-job (i.e. if job is spooled) or
per-printer subscriptions and whether or not they should be preserved
across power cycles?
Looking at the Notification Spec (draft-ietf-ipp-not-spec-07) the only
related discussion appears to be in Section 5.4.3 (When the Printer powers
up, it MUST set the value of this
(notify-lease-expiration-time) attribute in each persistent Subscription
Object...) which implies per-printer subscriptions may be expected to
across power cycle.
IBM Printing Systems
This archive was generated by hypermail 2b29 : Wed Sep 05 2001 - 16:23:33 EDT