draft-ietf-ipp-notify-get-04.txt   draft-ietf-ipp-notify-get-05.txt 
Internet Printing Protocol WG Robert Herriot (editor) Internet Printing Protocol WG Robert Herriot (editor)
INTERNET-DRAFT Xerox Corp. INTERNET-DRAFT Xerox Corp.
<draft-ietf-ipp-notify-get-04.txt> Carl Kugler <draft-ietf-ipp-notify-get-05.txt> Carl Kugler
Updates: RFC 2911 Harry Lewis Updates: RFC 2911 Harry Lewis
[Target category: standards track] IBM, Corp. [Target category: standards track] IBM, Corp.
Expires: January 17, 2002 July 17, 2001 Expires: April 17, 2002 October 17, 2001
Internet Printing Protocol (IPP): Internet Printing Protocol (IPP):
The 'ippget' Delivery Method for Event Notifications The 'ippget' Delivery Method for Event Notifications
Copyright (C) The Internet Society (2001). All Rights Reserved. Copyright (C) The Internet Society (2001). All Rights Reserved.
Status of this Memo: Status of this Memo:
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of [rfc2026]. Internet-Drafts are all provisions of Section 10 of [rfc2026]. Internet-Drafts are
skipping to change at page 1, line 47 skipping to change at page 1, line 47
Protocol/1.0 (IPP) [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910]. Protocol/1.0 (IPP) [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910].
This document specifies the 'ippget' Delivery Method for use with the This document specifies the 'ippget' Delivery Method for use with the
"IPP Event Notifications and Subscriptions" specification [ipp-ntfy]. "IPP Event Notifications and Subscriptions" specification [ipp-ntfy].
When IPP Notification [ipp-ntfy] is supported, the Delivery Method When IPP Notification [ipp-ntfy] is supported, the Delivery Method
defined in this document is one of the RECOMMENDED Delivery Methods defined in this document is one of the RECOMMENDED Delivery Methods
for Printers to support. for Printers to support.
The 'ippget' Delivery Method is a 'pull' Delivery Method with aspects The 'ippget' Delivery Method is a 'pull' Delivery Method with aspects
of a 'push' method as well. That is, when an Event occurs, the of a 'push' method as well. That is, when an Event occurs, the
Printer saves the Event Notification for a period of time called the Printer saves the Event Notification for a period of time called the
Event Notification Lease Time. The Notification Recipient fetches Event Life. The Notification Recipient fetches (pulls) Event
(pulls) Event Notifications using the Get-Notifications operation. Notifications using the Get-Notifications operation. If the
If the Notification Recipient has selected the option to wait for Notification Recipient has selected the Event Wait Mode option to
additional Event Notifications, the Printer continues to return wait for additional Event Notifications, the Printer continues to
return (similar to push) Event Notifications to the Notification
Recipient as Get-Notification responses as Events occur. This push
aspect is not a true 'push', since the Printer does not open the
connect, but rather continues to return responses as Events occur
using the connection originated by the Notification Recipient.
#@# this page exceeds 58 lines: 59 Either the Notification Recipient or the Printer can terminate Event
(similar to push) Event Notifications to the Notification Recipient Wait Mode without closing the connection.
as Get-Notification responses as Events occur. This push aspect is
not a true 'push', since the Printer does not open the connect, but
rather continues to return responses as Events occur using the
connection originated by the Notification Recipient.
Table of Contents Table of Contents
1 Introduction.....................................................5 1 Introduction.....................................................5
2 Terminology......................................................5 2 Terminology......................................................6
3 Model and Operation..............................................6
4 General Information..............................................8 3 Model and Operation..............................................7
5 Get-Notifications operation......................................9 4 General Information..............................................9
5.1 Get-Notifications Request.....................................11
5.2 Get-Notifications Response....................................13
6 Subscription Template Attributes................................18 5 Get-Notifications operation.....................................10
6.1 Subscription Template Attribute Conformance...................18 5.1 Get-Notifications Request.....................................12
6.2 Additional Information about Subscription Template Attributes.18 5.1.1 "notify-subscription-ids" (1setOf integer(1:MAX)):..........12
6.2.1 notify-recipient-uri (uri)..................................18 5.1.2 notify-sequence-numbers (1setOf integer(1:MAX)).............13
6.3 Subscription Description Attribute Conformance................19 5.1.3 "notify-wait" (boolean):....................................14
5.2 Get-Notifications Response....................................14
5.2.1 "notify-get-interval" (integer(0:MAX))......................17
5.2.2 "printer-up-time" (integer(1:MAX)):.........................19
5.2.3 "redirect-uri" (uri):.......................................19
7 Attributes only in Event Notifications..........................19 6 Additional Information about Subscription Template Attributes...23
7.1 "notify-get-interval" (integer(0:MAX))........................19 6.1 notify-recipient-uri (uri)....................................23
8 Additional Printer Description Attributes.......................20 7 Subscription Description Attributes.............................24
8.1 ippget-event-time-to-live (integer(0:MAX))....................20
9 New Values for Existing Printer Description Attributes..........21 8 Additional Printer Description Attributes.......................24
9.1 notify-schemes-supported (1setOf uriScheme)...................21 8.1 ippget-event-life (integer(15:MAX))...........................24
9.2 operations-supported (1setOf type2 enum)......................21
10 New Status Codes...............................................21 9 New Values for Existing Printer Description Attributes..........25
10.1 redirection-other-site (0x0300)..............................21 9.1 notify-schemes-supported (1setOf uriScheme)...................25
9.2 operations-supported (1setOf type2 enum)......................26
11 The IPPGET URL Scheme..........................................22 10 New Status Codes...............................................26
11.1 The IPPGET URL Scheme Applicability and Intended Usage.......22 10.1 successful-ok-events-complete (0x0007).......................26
11.2 The IPPGET URL Scheme Associated Port........................22 10.2 redirection-other-site (0x0300)..............................26
11.3 The IPPGET URL Scheme Associated MIME Type...................22
11.4 The IPPGET URL Scheme Character Encoding.....................22
11.5 The IPPGET URL Scheme Syntax in ABNF.........................23
11.5.1 IPPGET URL Examples........................................24
11.5.2 IPPGET URL Comparisons.....................................24
12 Encoding and Transport.........................................25 11 The IPPGET URL Scheme..........................................27
11.1 The IPPGET URL Scheme Applicability and Intended Usage.......27
11.2 The IPPGET URL Scheme Associated Port........................27
11.3 The IPPGET URL Scheme Associated MIME Type...................27
11.4 The IPPGET URL Scheme Character Encoding.....................28
11.5 The IPPGET URL Scheme Syntax in ABNF.........................28
11.5.1 IPPGET URL Examples........................................29
11.5.2 IPPGET URL Comparisons.....................................30
13 Conformance Requirements.......................................26 12 Encoding and Transport.........................................30
13.1 Conformance for IPP Printers.................................26 13 Conformance Requirements.......................................31
13.2 Conformance for IPP Clients..................................27 13.1 Conformance for IPP Printers.................................31
13.2 Conformance for IPP Clients..................................32
14 IANA Considerations............................................28 14 IANA Considerations............................................33
14.1 Operation Registrations......................................28 14.1 Additional attribute value registrations for existing attributes
14.2 Additional attribute value registrations for existing attributes 33
28 14.1.1 Additional values for the "notify-schemes-supported" Printer
14.2.1 Additional values for the "notify-schemes-supported" Printer attribute..............................................33
attribute..............................................28 14.1.2 Additional values for the "operations-supported" Printer
14.2.2 Additional values for the "operations-supported" Printer attribute..............................................34
attribute..............................................29 14.2 Operation Registrations......................................34
14.3 Attribute Registrations......................................29 14.3 Attribute Registrations......................................35
14.4 Status code Registrations....................................29 14.4 Status code Registrations....................................35
15 Internationalization Considerations............................30 15 Internationalization Considerations............................35
16 Security Considerations........................................30 16 Security Considerations........................................35
17 References.....................................................30 17 References.....................................................36
18 Authors' Addresses.............................................32 18 Authors' Addresses.............................................38
19 Description of Base IPP documents..............................33 19 Description of Base IPP documents..............................39
20 Full Copyright Statement.......................................35 20 Full Copyright Statement.......................................40
Table of Tables Table of Tables
Table 1 " Information about the Delivery Method....................8 Table 1 - Information about the Delivery Method....................9
Table 2 " Attributes in Event Notification Content................16 Table 2 - Combinations of "notify-wait", "status-code", and "notify-
Table 3 " Additional Attributes in Event Notification Content for Job get-interval" .................................................18
Events........................................................17 Table 3 - Attributes in Event Notification Content................21
Table 4 " Combinations of Events and Subscribed Events for "job- Table 4 - Additional Attributes in Event Notification Content for Job
impressions-completed"........................................17 Events ........................................................22
Table 5 " Additional Attributes in Event Notification Content for Table 5 - Combinations of Events and Subscribed Events for "job-
Printer Events................................................18 impressions-completed" ........................................23
Table 6 " Operation-id assignments................................21 Table 6 - Additional Attributes in Event Notification Content for
Table 7 " The "event-notification-attributes-tag" value...........26 Printer Events ................................................23
Table 7 - Operation-id assignments................................26
Table 8 - The "event-notification-attributes-tag" value...........31
1 Introduction 1 Introduction
The "IPP Event Notifications and Subscriptions" document [ipp-ntfy] The "IPP Event Notifications and Subscriptions" document [ipp-ntfy]
defines an OPTIONAL extension to Internet Printing Protocol/1.0 (IPP) defines an OPTIONAL extension to Internet Printing Protocol/1.0 (IPP)
[RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910]. For a description [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910]. For a description
of the base IPP documents, see section 19. The [ipp-ntfy] extension of the base IPP documents, see section 19. The [ipp-ntfy] extension
defines operations that a client can perform in order to create defines operations that a client can perform in order to create
Subscription Objects in a Printer and carry out other operations on Subscription Objects in a Printer and carry out other operations on
them. A Subscription Object represents a Subscription abstraction. them. A Subscription Object represents a Subscription abstraction.
skipping to change at page 5, line 36 skipping to change at page 5, line 36
The "IPP Event Notifications and Subscriptions" document [ipp-ntfy] The "IPP Event Notifications and Subscriptions" document [ipp-ntfy]
specifies that each Delivery Method is defined in another document. specifies that each Delivery Method is defined in another document.
This document is one such document, and it specifies the 'ippget' This document is one such document, and it specifies the 'ippget'
delivery method. When IPP Notification [ipp-ntfy] is supported, the delivery method. When IPP Notification [ipp-ntfy] is supported, the
Delivery Method defined in this document is one of the RECOMMENDED Delivery Method defined in this document is one of the RECOMMENDED
Delivery Methods for Printers to support. Delivery Methods for Printers to support.
The 'ippget' Delivery Method is a 'pull' Delivery Method with aspects The 'ippget' Delivery Method is a 'pull' Delivery Method with aspects
of a 'push' method as well. That is, when an Event occurs, the of a 'push' method as well. That is, when an Event occurs, the
Printer saves the Event Notification for a period of time called the Printer saves the Event Notification for a period of time called the
Event Notification Lease Time. The Notification Recipient fetches Event Life. The Notification Recipient fetches (pulls) the Event
(pulls) the Event Notifications using the Get-Notifications Notifications using the Get-Notifications operation. This operation
operation. This operation causes the Printer to return all Event causes the Printer to return all Event Notifications held for the
Notifications held for the Notification Recipient. If the specified Subscription object(s). If the Notification Recipient has
Notification Recipient has selected the option to wait for additional selected the Event Wait Mode option to wait for additional Event
Event Notifications, the Printer continues to return (similar to Notifications, the Printer continues to return (similar to push)
push) Event Notifications to the Notification Recipient as Get- Event Notifications to the Notification Recipient as Get-Notification
Notification responses as Events occur. This push aspect is not a responses as Events occur. This push aspect is not a true 'push',
true 'push', since the Printer does not open the connect, but rather since the Printer does not open the transaction, but rather continues
continues to return responses as Events occur using the connection to return responses as Events occur using the transaction originated
originated by the Notification Recipient. by the Notification Recipient.
The Notification Recipient can terminate Event Wait Mode (without
closing the connection) by supplying the "notify-wait" attribute with
a 'false' value in a subsequent Get-Notifications request.
Similarly, the Printer can terminate Event Wait Mode (without closing
the connection) by returning the "notify-get-interval" operation
attribute in a Get-Notifications response which tells the
Notification Recipient how long to wait before trying again.
2 Terminology 2 Terminology
This section defines the following terms that are used throughout This section defines the following terms that are used throughout
this document: this document:
This document uses the same terminology as [RFC2911], such as This document uses the same terminology as [RFC2911], such as
"client", "Printer", "Job", "attribute", "attribute value", "client", "Printer", "Job", "attribute", "attribute value",
"keyword", "operation", "request", "response", and "support". "keyword", "operation", "request", "response", and "support".
Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD
NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to
conformance as defined in RFC 2119 [RFC2119] and [RFC2911] section conformance as defined in RFC 2119 [RFC2119] and [RFC2911] section
12.1. If an implementation supports the extension defined in this 12.1. If an implementation supports the extension defined in this
document, then these terms apply; otherwise, they do not. These document, then these terms apply; otherwise, they do not. These
terms define conformance to this document only; they do not affect terms define conformance to this document only; they do not affect
conformance to other documents, unless explicitly stated otherwise. conformance to other documents, unless explicitly stated otherwise.
Event Notification Lease: The lease that is associated with an Event Event Life: The length of time in seconds after an Event occurs
Notification. When the lease expires, the Printer discards the during which the Printer will return that Event in a Event
associated Event Notification. Notification in a Get-Notifications response. After the Event
Life expires, the Printer will no longer return an Event
Event Notification Lease Time: The expiration time assigned to a Notification for that Even in a Get-Notifications response.
lease that is associated with an Event Notification.
Event Notification Attributes Group: The attributes group in a Event Notification Attributes Group: The attributes group in a
response that contains attributes that are part of an Event response that contains attributes that are part of an Event
Notification. Notification.
Event Wait Mode: The mode requested by a Notification Recipient Event Wait Mode: The mode requested by a Notification Recipient
client in its Get-Notifications Request and granted by a Printer to client in its Get-Notifications Request and granted by a Printer
keep the connection open where the Printer sends subsequent Event to keep the connection open where the Printer sends subsequent
Notifications to the Notification Recipient as they occur as Event Notifications to the Notification Recipient as they occur
additional Get-Notification Responses. as additional Get-Notification Responses.
Other capitalized terms, such as Notification Recipient, Event Other capitalized terms, such as Notification Recipient, Event, Event
Notification, Compound Event Notification, Printer, etc., are Notification, Compound Event Notification, Printer, etc., are
defined in [ipp-ntfy], have the same meanings, and are not reproduced defined in [ipp-ntfy], have the same meanings, and are not
here. reproduced here. However, for convenience the following key
terms are reproduced here:
Event - some occurrence (either expected or unexpected) within the
printing system of a change of state, condition, or
configuration of a Job or Printer object. An Event occurs only
at one instant in time and does not span the time the physical
Event takes place. For example, jam-occurred and jam-cleared
are two distinct, instantaneous Events, even though the jam may
last for a while.
Event Notification - the information about an Event that the Printer
sends when an Event occurs.
3 Model and Operation 3 Model and Operation
In a Subscription Creation Operation, when the value of the "notify- In a Subscription Creation Operation, when the value of the "notify-
recipient-uri" attribute has the scheme 'ippget', the client is recipient-uri" attribute has the scheme 'ippget', the client is
requesting that the Printer use the 'ippget' Delivery Method for the requesting that the Printer use the 'ippget' Delivery Method for the
Event Notifications associated with the new Subscription Object. The Event Notifications associated with the new Subscription Object. The
client SHOULD choose a value for the address part of the "notify- client SHOULD choose a value for the address part of the "notify-
recipient-uri" attribute that uniquely identifies the Notification recipient-uri" attribute that uniquely identifies the Notification
Recipient. Recipient.
When an Event occurs, the Printer MUST generate an Event Notification When an Event occurs, the Printer MUST generate an Event Notification
and MUST assign it the Event Notification Lease Time. The Printer and MUST assign it the Event Life. The Printer MUST hold an Event
MUST hold an Event Notification for its assigned Event Notification Notification for its assigned Event Life.
Lease Time. The Printer MUST assign the same Event Notification
Lease Time to each Event Notification.
When a Notification Recipient wants to receive Event Notifications, When a Notification Recipient wants to receive Event Notifications
it performs the Get-Notifications operation, which causes the Printer for a Subscription object, it performs the Get-Notifications
to return all un-expired Event Notifications held for the operation supplying the Subscription object's subscription-id, which
Notification Recipient. If the Notification Recipient has selected causes the Printer to return all un-expired Event Notifications held
the Event Wait Mode option to wait for additional Event for that Subscription object. If the Notification Recipient has
selected the Event Wait Mode option to wait for additional Event
Notifications, the response to the Get-Notifications request Notifications, the response to the Get-Notifications request
continues indefinitely as the Printer continues to send Event continues indefinitely as the Printer continues to send Event
Notifications in the response as Events occur. For the Get- Notifications in the response as Events occur for that Subscription
Notification operation, the Printer sends only those Event object.
Notifications that are generated from Subscription Objects whose
"notify-recipient-uri" attribute value equals the value of the
"notify-recipient-uri" Operation Attribute in the Get-Notifications
operation.
If a Notification Recipient performs the Get-Notifications operation
twice in quick succession, it will receive nearly the same Event
Notification both times because most of the Event Notifications are
those that the Printer saves for a few seconds after the Event
occurs. There are two possible differences. Some old Event
Notifications may not be present in the second response because their
Event Notification Leases have expired. Some new Event Notifications
may be present in the second response but not the first response,
because they occurred after the first response.
When the Notification Recipient requests Event Notifications for per- When the Notification Recipient requests Event Notifications for per-
Job Subscription Objects, the Notification Recipient typically Job Subscription Objects, the Notification Recipient typically
performs the Get-Notifications operation within a second of performs the Get-Notifications operation within a second of
performing the Subscription Creation operation. Because the Printer performing the Subscription Creation operation. Because the Printer
is likely to save Event Notifications for several seconds, the MUST save Event Notifications for at least 15 seconds (see section
Notification Recipient is unlikely to miss any Event Notifications 8.1), the Notification Recipient is unlikely to miss any Event
that occur between the Subscription Creation and the Get- Notifications that occur between the Subscription Creation and the
Notifications operation. Get-Notifications operation.
ISSUE 01: Although we agreed to extend Job Creation operations to
support Event Wait Mode, it seems to be an unnecessary complication,
since the Printer MUST keep events for at least 15 seconds. So OK
NOT to add the "notify-wait" (boolean) operation attribute to Job
Creation operations and NOT have to have Job Creation responses
return Event Notification Groups (in addition to returning
Subscription Attribute Groups).
The 'ippget' Delivery Method is designed primarily for (1) a client
that wants to get Events (from the job's per-Job Subscription object)
for a job that it has submitted and (2) for a privileged client that
wants to get all job or printer Events from a per-Printer
Subscription object. If several groups of users expect to receive
jobs from other users (FAX paradigm) and each group has a different
designated person, say, a secretary, to receive job completion
Events, the Printer should be configured to support multiple URLs,
one for each group. Then the designated person can run an
application that gets the events for jobs submitted to that URL from
the per-Printer Subscription object that the application creates.
4 General Information 4 General Information
If a Printer supports this Delivery Method, the following are its If a Printer supports this Delivery Method, the following are its
characteristics. characteristics.
Table 1 " Information about the Delivery Method Table 1 - Information about the Delivery Method
Document Method Conformance Requirement Delivery Method Document Method Conformance Requirement Delivery Method
Realization Realization
1. What is the URL scheme name for the ippget 1. What is the URL scheme name for the ippget
Delivery Method? Delivery Method?
2. Is the Delivery Method REQUIRED, RECOMMENDED 2. Is the Delivery Method REQUIRED, RECOMMENDED
RECOMMENDED or OPTIONAL for an IPP RECOMMENDED or OPTIONAL for an IPP
Printer to support? Printer to support?
3. What transport and delivery protocols IPP with one new 3. What transport and delivery protocols IPP with one new
does the Printer use to deliver the Event operation. does the Printer use to deliver the operation.
Notification Content, i.e., what is the Event Notification Content, i.e., what
entire network stack? is the entire network stack?
4. Can several Event Notifications be Yes. 4. Can several Event Notifications be Yes.
combined into a Compound Event combined into a Compound Event
Notification? Notification?
5. Is the Delivery Method initiated by the This Delivery Method
Notification Recipient (pull), or by the is a pull method 5. Is the Delivery Method initiated by This Delivery Method is
Printer (push)? with aspects of a the Notification Recipient (pull), or a pull method with
push method, though by the Printer (push)? aspects of a push
the Printer does not method, though the
initiate the Printer does not
connection. initiate the connection.
6. Is the Event Notification content Machine Machine Consumable
Consumable or Human Consumable? 6. Is the Event Notification content Machine Consumable
7. What section in this document answers the Section 5 Machine Consumable or Human
following question? For a Machine Consumable?
7. What section in this document answers Section 5
the following question? For a Machine
Consumable Event Notification, what is Consumable Event Notification, what is
the representation and encoding of values the representation and encoding of
defined in section 9.1 of [ipp-ntfy] and values defined in section 9.1 of [ipp-
the conformance requirements thereof? For ntfy] and the conformance requirements
a Human Consumable Event Notification, thereof? For a Human Consumable Event
what is the representation and encoding Notification, what is the
of pieces of information defined in Notification, what is the
section 9.2 of [ipp-ntfy] and the representation and encoding of pieces
conformance requirements thereof? of information defined in section 9.2
8. What are the latency and reliability of Same as IPP and the of [ipp-ntfy] and the conformance
the transport and delivery protocol? underlying HTTP requirements thereof?
transport
8. What are the latency and reliability Same as IPP and the
of the transport and delivery underlying HTTP
protocol? transport
9. What are the security aspects of the Same as IPP and the 9. What are the security aspects of the Same as IPP and the
transport and delivery protocol, e.g., underlying HTTP transport and delivery protocol, e.g., underlying HTTP
how it is handled in firewalls? transport how it is handled in firewalls? transport and in the
10. What are the content length restrictions? None same direction, so no
11. What are the additional values or pieces None new firewall
of information that a Printer sends in an considerations.
Event Notification content and the
conformance requirements thereof? 10.What are the content length None
restrictions?
11.What are the additional values or
pieces of information that a Printer
sends in an Event Notification content
and the conformance requirements
thereof? None
12. What are the additional Subscription None 12. What are the additional Subscription None
Template and/or Subscription Description Template and/or Subscription
attributes and the conformance
requirements thereof?
13. What are the additional Printer None
Description attributes and the Description attributes and the
conformance requirements thereof? conformance requirements thereof?
13.What are the additional Printer "ipp-event-life"
Description attributes and the (integer (15: MAX))
conformance requirements thereof?
5 Get-Notifications operation 5 Get-Notifications operation
This operation is issued by a client acting in the role of a This operation is issued by a client acting in the role of a
Notification Recipient and causes the Printer to return all Event Notification Recipient requesting the Printer to return all Event
Notifications held for the Notification Recipient. Notifications held for the identified Subscription object(s).
A Printer MUST support this operation. A Printer MUST support this operation.
When a Printer performs this operation, it MUST return all and only When a Printer performs this operation, it MUST return all and only
those Event Notifications: those Event Notifications:
1. Whose associated Subscription Object's "notify-subscription-id" 1. Whose associated Subscription Object's "notify-subscription-id"
attribute equals the "notify-subscription-id" Operation Subscription Description attribute equals one of the values of
attribute if supplied AND the "notify-subscription-ids" (1setOf integer(1:MAX)) operation
attribute AND
2. Whose associated Subscription Object's "notify-recipient-uri" 2. Whose associated Subscription Object's "notify-recipient-uri"
attribute equals the "notify-recipient-uri" Operation attribute attribute matches the scheme value of 'ippget' using the (case-
AND insensitive) matching rules in section 11.5.2 AND
3. Whose associated Subscription Object's "notify-recipient-uri" 3. Whose "notify-sequence-number" is equal to or greater than the
attribute matches the scheme value of 'ippget' using the corresponding value of the "notify-sequence-numbers (1setOf
matching rules in section 11.5.2 AND integer(1:MAX)) operation attribute, if supplied AND
4. Whose Event Notification Lease Time has not yet expired AND 4. Whose Event Life has not yet expired AND
5. Where the Notification Recipient is the owner of or has read- 5. Where the Notification Recipient is the owner of or has read-
access rights to the associated Subscription Object. access rights to the identified Subscription Object.
The Printer has the following options for responding to a Get-
Notifications Request:
#@# next line is > 72 characters: 73
1. The Printer can reject the request and return the 'server-error-
busy' status code, if the Printer is too busy to accept this
operation at this time. In this case, the Printer MUST return
the "get-notify-interval" attribute to indicate when the client
should try again.
2. If the Notification Recipient did not request Event Wait Mode,
the Printer MUST respond to this operation immediately with
whatever Event Notifications it currently holds and return the
"notify-get-interval" attribute with number of seconds from now
at which the Notification Recipient MAY repeat the Get-
Notifications Request to get future Event Notifications.
3. If the Notification Recipient requested Event Wait Mode, the The Notification Recipient client can request Event Wait Mode by
Printer MUST respond to this operation immediately with whatever supplying the "notify-wait" operation attribute with a 'true' value.
Event Notifications it currently holds MUST continue to send
Event Notifications as they occur until all of the associated
Subscription Objects are cancelled. A Subscription Object is
cancelled either via the Cancel-Subscription operation or by the
Printer (e.g., the Subscription Object is cancelled when the
associated Job completes and is no longer in the Job Retention
or Job History phase - see the "ippget-event-time-to-live
(integer(0:MAX))" attribute discussion in section 8.1).
However, the Printer MAY decide to terminate Event Wait Mode at
any time, including in the first response. In this case the
Printer MUST return an additional Event Notification Attributes
Group that contains the single "notify-get-interval" attribute.
This attribute indicates that the Printer wishes to leave Event
Wait Mode and the number of seconds in the future that the
Notification Recipient SHOULD try the Get-Notifications
operation again. The Notification Recipient MUST accept this
response and MUST disconnect. If the Notification Recipient
does not disconnect, the Printer SHOULD do so.
If the Notification Recipient wishes to terminate the Get- The Notification Recipient client can terminate Event Wait Mode
Notifications operation, it can close the connection. See section 12 (without closing the connection) by supplying the "notify-wait"
for the encoding and transport rules for the Get-Notifications attribute with a 'false' value in a subsequent Get-Notifications
Response for the Event Wait Mode. request. Similarly, the Printer can terminate Event Wait Mode
(without closing the connection) by returning the "notify-get-
interval" operation attribute in a Get-Notifications response which
tells the Notification Recipient how long to wait before trying
again.
The Printer MUST accept the request in any state (see [RFC2911] The Printer MUST accept the request in any state (see [RFC2911]
"printer-state" and "printer-state-reasons" attributes) and MUST "printer-state" and "printer-state-reasons" attributes) and MUST
remain in the same state with the same "printer-state-reasons" remain in the same state with the same "printer-state-reasons"
values. values.
Access Rights: If the policy of the Printer is to allow all users to Access Rights: If the policy of the Printer is to allow all users to
access all Event Notifications, then the Printer MUST accept this access all Event Notifications, then the Printer MUST accept this
operation from any user. Otherwise, the authenticated user (see operation from any user. Otherwise, the authenticated user (see
[RFC2911] section 8.3) performing this operation MUST either be the [RFC2911] section 8.3) performing this operation MUST be the owner of
owner of each Subscription Object identified by the "notify- each Subscription Object identified by the "notify-subscription-ids"
recipient-uri" Operation attribute (as determined during a operation attribute (as returned during a Subscription Creation
Subscription Creation Operation) or an operator or administrator of Operation) or an operator or administrator of the Printer (see
the Printer (see [RFC2911] Sections 1 and 8.5). Otherwise, the IPP [RFC2911] Sections 1 and 8.5). Otherwise, the IPP object MUST reject
object MUST reject the operation and return: 'client-error- the operation and return: 'client-error-forbidden', 'client-error-
forbidden', 'client-error-not-authenticated', or 'client-error-not- not-authenticated', or 'client-error-not-authorized' status code as
authorized' status code as appropriate. appropriate.
5.1 Get-Notifications Request 5.1 Get-Notifications Request
The following groups of attributes are part of the Get-Notifications The following groups of attributes are part of the Get-Notifications
Request: Request:
Group 1: Operation Attributes Group 1: Operation Attributes
Natural Language and Character Set: Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language" The "attributes-charset" and "attributes-natural-language"
attributes as described in [RFC2911] section 3.1.4.1. attributes as described in [RFC2911] section 3.1.4.1.
Target: Target:
The "printer-uri" (uri) operation attribute which is the target The "printer-uri" (uri) operation attribute which is the target
for this operation as described in [RFC2911] section 3.1.5. for this operation as described in [RFC2911] section 3.1.5.
Requesting User Name: Requesting User Name:
The "requesting-user-name" (name(MAX)) attribute SHOULD be The "requesting-user-name" (name(MAX)) attribute SHOULD be
supplied by the client as described in [RFC2911] section 8.3. supplied by the client as described in [RFC2911] section 8.3.
"notify-subscription-id" (integer(1:MAX)): 5.1.1 "notify-subscription-ids" (1setOf integer(1:MAX)):
The client SHOULD supply this attribute, if known, and the
client is only monitoring a single Subscription object. The
Printer object MUST support this attribute. If supplied, but
no Subscription Object exists with this identifier, the Printer
MUST return the 'client-error-not-found' status code.
If supplied and the identified Subscription Object exists, the This attribute identifies one or more Subscription objects for
Printer MUST check that the Subscription Object's "notify- which Events are requested. The client MUST supply this
recipients-uri" attribute scheme is 'ippget' (case insensitive- attribute with at least one value. The Printer object MUST
match - see section 11.5.2). If the scheme does not match support this attribute with multiple values.
'ippget', the Printer MUST reject the request and return the
'client-error-uri-scheme-not-supported' status code.
Note: If Notification Recipients supplies this attribute, if If no Subscription Object exists with the supplied identifier,
known, then the Event Notifications will be sent in time stamp the Printer MUST return the 'client-error-not-found' status
order since only one Subscription object is involved (see code.
"Event Notification Ordering" requirements in [ipp-ntfy]
section 9). Supplying this attribute also reduces the Event
processing time on the Printer since the Printer doesn't have
to search all of the Subscription Objects in order to match the
"notify-recipient-uri" operation attribute (see next
attribute).
"notify-recipient-uri" (uri(255)): If an identified Subscription Object does not have a "notify-
The client MAY supply this attribute whether or not it also recipients-uri" Subscription attribute with 'ippget' scheme
supplies the "notify-subscription-id" operation attribute. The (case insensitive-match - see section 11.5.2), the Printer MUST
Printer object MUST support this attribute. If the client reject the request and return the 'client-error-uri-scheme-not-
supplies neither the "notify-subscription-id" nor the "notify- supported' status code.
recipient-uri", the Printer MUST reject the request and return
the 'client-error-bad-request' status code.
If the supplied scheme is not ippget (case insensitive-match - Note: The name of both the "notify-subscription-ids" and
see section 11.5.2), the Printer MUST reject the request and "notify-sequence-numbers" end in 's', since they are
return the 'client-error-uri-scheme-not-supported' status code. multi-valued. However, there are other occurrences of
these attribute names without the 's' that are single
valued.
If the client also supplied the "notify-subscription-id" 5.1.2 notify-sequence-numbers (1setOf integer(1:MAX))
attribute, then the value of this attribute MUST match the
"notify-recipient-uri" Subscription Description attribute for
the identified Subscription object. If they do not match, the
Printer MUST return the 'client-error-not-found' status code.
If the client did not supply the "notify-subscription-id" This attribute specifies one or more lowest Event Notification
operation attribute, the Printer matches the value of this sequence number values for the Subscription objects identified
"notify-recipient-uri" attribute against the value of the by the corresponding values of the "notify-subscription-ids"
"notify-recipient-uri" Subscription Description attribute in operation attribute. The Notification Recipient SHOULD supply
each Subscription Object in the Printer using the URI matching this attribute and the number of values SHOULD be the same as
rules specified in section 11.5.2. If there are no matches, the the number of values of the "notify-subscriptions-ids"
IPP Printer MUST return the 'client-error-not-found' status attribute. The Printer MUST support this attribute with
code. multiple values.
The value of this attribute is defined to be shorter (255 The Printer MUST NOT return Notification Events with lower
octets) than the 'uri' attribute syntax (1023 octets) in sequence numbers for the corresponding Subscription object.
[RFC2911], since this uri is used for identification, not for Therefore, by supplying the proper values for this attribute
locating a network resource. the Notification Recipient can prevent getting the same Event
Notifications from a Subscription object that were returned on
a previous Get-Notifications request. The Notification
Recipient SHOULD remember the highest "notify-sequence-number"
value returned for each Subscription object requested and
SHOULD pass that value for each requested Subscription object
on the next Get-Notifications request.
The [ipp-ntfy] specification REQUIRES that Subscription If the Notification Recipient supplies fewer values for this
Object's "notify-recipient-uri" attribute be returned in any attribute (including omitting this attribute) than for the
operation with the identical representation as supplied by the "notify-subscription-ids" operation attribute, the Printer
original Subscribing Client in the Subscription Creation assumes a '1' value for each missing value. A value of '1'
Request. Therefore the Printer implementation MUST use other causes the Printer to return any un-expired Event Notification
means to perform the URI match than changing the Subscription for that Subscription object, since '1' is the lowest possible
Object's original "notify-recipient-uri" value to a canonical sequence number. If the Notification Recipient supplies more
form. values for this attribute than the number of values for the
"notify-subscription-ids" operation attribute, the Printer
ignores the extra values.
Note: this attribute allows a subscribing client to pick URLs Note: If a Notification Recipient performs two consecutive Get-
that are unique, e.g. the client's own URL or a friend's URL, Notifications operations with the same value for "notify-
which in both cases is likely the URL of the person's host. An sequence-number" (or omits the attribute), the time stamp of
application could make a URL unique for each application. the first Event Notification in the second Get-Notifications
Response may be less than the time stamp of the last Event
Notification in the first Get-Notification Response. This
happens because the Printer sends all unexpired Event
Notification with a sequence number equal or higher according
to the ordering specified in [ipp-ntfy] and some Event
Notifications from the first Get-Notifications operation may
not have expired by the time the second Get-Notifications
operation occurs.
"notify-wait" (boolean): 5.1.3 "notify-wait" (boolean):
The client MAY supply this attribute. The Printer object MUST
support both values of this attribute. If the value is 'true', This value indicates whether or not the Notification Recipient
the client is requesting Event Wait Mode. See the beginning of wants Event Wait Mode. The client MAY supply this attribute.
section 5 for the rules for Event Wait Mode. The Printer object MUST support both values of this attribute.
If the client supplies the 'false' value or omits this
attribute, the client is not requesting Event Wait Mode. If
the value is 'true', the client is requesting Event Wait Mode.
See the beginning of section 5.2 for the rules for Event Wait
Mode.
5.2 Get-Notifications Response 5.2 Get-Notifications Response
The Printer has the following options for responding to a Get-
Notifications Request:
1. The Printer can reject the request and return the 'server-error-
busy' status code, if the Printer is too busy to accept this
operation at this time. In this case, the Printer MUST return
the "get-notify-interval" operation attribute to indicate when
the client SHOULD try again.
2. If the Notification Recipient did not request Event Wait Mode
("notify-wait-mode" = 'false' or omitted), the Printer MUST
return immediately whatever Event Notifications it currently
holds in the requested Subscription object(s) and MUST return
the "notify-get-interval" operation attribute with number of
seconds from now at which the Notification Recipient SHOULD
repeat the Get-Notifications Request to get future Event
Notifications.
3. If the Notification Recipient requested Event Wait Mode
("notify-wait-mode" = 'true'), the Printer MUST return
immediately whatever Event Notifications it currently holds in
the requested Subscription object(s) and MUST continue to return
Event Notifications as they occur until all of the requested
Subscription Objects are canceled. A Subscription Object is
canceled either via the Cancel-Subscription operation or by the
Printer (e.g., the Subscription Object is canceled when the
associated Job completes and is no longer in the Job Retention
or Job History phase - see the "ippget-event-life
(integer(15:MAX))" attribute discussion in section 8.1).
However, the Printer MAY decide to terminate Event Wait Mode at
any time, including in the first response. In this case the
Printer MUST return the "notify-get-interval" operation
attribute. This attribute indicates that the Printer wishes to
leave Event Wait Mode and the number of seconds in the future
that the Notification Recipient SHOULD try the Get-Notifications
operation again. The Notification Recipient MUST accept this
response and MUST disconnect. If the Notification Recipient
does not disconnect, the Printer SHOULD do so.
From the Notification Recipient's view, the response appears as an
initial burst of data, which includes the Operation Attributes Group
and one Event Notification Attributes Group per Event Notification
that the Printer is holding. After the initial burst of data, if the
Notification Recipient has selected the Event Wait Mode option to
wait for additional Event Notifications, the Notification Recipient
receives occasional Event Notification Attribute Groups. Proxy
servers may delay some Event Notifications or cause time-outs to
occur. The client MUST be prepared to perform the Get-Notifications
operation again when time-outs occur.
Each attribute is encoded using the IPP rules for encoding attributes
[RFC2910] and MAY be encoded in any order. Note: the Get-Jobs
response in [RFC2911] acts as a model for encoding multiple groups of
attributes. See section 12 for the encoding and transport rules.
The following groups of attributes are part of the Get-Notifications The following groups of attributes are part of the Get-Notifications
Response: Response:
Group 1: Operation Attributes Group 1: Operation Attributes
Status Message: Status Message:
In addition to the REQUIRED status code returned in every In addition to the REQUIRED status code returned in every
response, the response OPTIONALLY includes a "status-message" response, the response OPTIONALLY includes a "status-message"
(text(255)) and/or a "detailed-status-message" (text(MAX)) (text(255)) and/or a "detailed-status-message" (text(MAX))
operation attribute as described in [RFC2911] sections 13 and operation attribute as described in [RFC2911] sections 13 and
3.1.6. 3.1.6.
The Printer can return any status codes defined in [RFC2911]. The Printer can return any status codes defined in [RFC2911].
If the status code is not 'successful-xxx', the Printer MUST If the status code is not 'successful-xxx', the Printer MUST
NOT return any Event Notification Attribute groups. The NOT return any Event Notification Attribute groups. The
following is a description of the important status codes: following is a description of the important status codes:
successful-ok: the response contains all Event Notification successful-ok: the response contains all Event Notification
associated with the specified "notify-recipient-uri". If associated with the specified subscription-ids that had
the specified Subscription Objects have no associated been supplied in the "notify-subscription-ids" operation
Event Notification, the response MUST contain zero Event attribute in the request. If the requested Subscription
Notifications. Objects have no associated Event Notification, the
response MUST contain zero Event Notifications.
successful-ok-events-complete: indicate when this return
is the last return for all Subscription objects that
match the request, whether or not there are Event
Notifications being returned. This condition occurs for
Event Wait Mode with Notification Recipients waiting for
responses when the Subscription Object is: (1) canceled
with a Cancel-Subscription operation, (2) deleted when
the Per-Printer Subscription lease time expires, or (3)
when the 'job-completed' event occurs for a Per-Job
Subscription. This condition also occurs for a Get-
Notifications request that a Notification Recipient makes
after the job completes, but before the Event Life
expires. See section 10.1.
client-error-not-found: The Printer has no Subscription client-error-not-found: The Printer has no Subscription
Object's whose "notify-recipient-uri" attribute equals Object's whose "notify-subscription-id" attribute equals
the "notify-recipient-uri" Operation attribute, if any of the values of the "notify-subscription-ids"
supplied or whose "notify-subscription-id" attribute operation attribute supplied.
equals the "notify-subscription-id" Operation attribute,
if supplied.
server-error-busy: The Printer is too busy to accept this server-error-busy: The Printer is too busy to accept this
operation. If the "notify-get-interval" operation operation. The Printer SHOULD return the "notify-get-
attribute is present in the Operation Attributes of the interval" operation attribute in the Operation Attributes
response, then the Notification Recipient SHOULD wait for of the response, then the Notification Recipient SHOULD
the number of seconds specified by the "notify-get- wait for the number of seconds specified by the "notify-
interval" attribute before performing this operation get-interval" operation attribute before performing this
again. If the "notify-get-interval" Operation Attribute operation again. If the "notify-get-interval" Operation
is not present, the Notification Recipient SHOULD use the Attribute is not present, the Notification Recipient
normal network back-off algorithms for determining when SHOULD use the normal network back-off algorithms for
to perform this operation again. determining when to perform this operation again.
redirection-other-site: The Printer does not handle this redirection-other-site: The Printer does not handle this
operation and requests the Notification Recipient to operation and requests the Notification Recipient to
perform the operation again with the uri specified by the perform the operation again with the uri specified by the
"redirect-uri" Operation Attribute in the response. "redirect-uri" Operation Attribute in the response. See
section 10.2.
Natural Language and Character Set: Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language" The "attributes-charset" and "attributes-natural-language"
attributes as described in [RFC2911] section 3.1.4.2. attributes as described in [RFC2911] section 3.1.4.2.
The Printer MUST use the values of "notify-charset" and The Printer MUST use the values of "notify-charset" and
"notify-natural-language", respectively, from one Subscription "notify-natural-language", respectively, from one Subscription
Object associated with the Event Notifications in this Object associated with the Event Notifications in this
response. response.
Normally, there is only one matched Subscription Object, or the Normally, there is only one matched Subscription Object, or the
value of the "notify-charset" and "notify-natural-language" value of the "notify-charset" and "notify-natural-language"
attributes is the same in all Subscription Objects. If not, the attributes is the same in all Subscription Objects. If not, the
Printer MUST pick one Subscription Object from which to obtain Printer MUST pick one Subscription Object from which to obtain
the value of these attributes. The algorithm for picking the the value of these attributes. The algorithm for picking the
Subscription Object is implementation dependent. The choice of Subscription Object is implementation dependent. The choice of
natural language is not critical because 'text' and 'name' natural language is not critical because 'text' and 'name'
values can override the "attributes-natural-language" Operation values can override the "attributes-natural-language" operation
attribute. The Printer's choice of charset is critical because attribute. The Printer's choice of charset is critical because
a bad choice may leave it unable to send some 'text' and 'name' a bad choice may leave it unable to send some 'text' and 'name'
values accurately. values accurately.
"printer-up-time" (integer(1:MAX)): 5.2.1 "notify-get-interval" (integer(0:MAX))
The value of this operation attribute is the number of seconds
that the Notification Recipient SHOULD wait before trying the
Get-Notifications operation again. The Printer MUST return
this operation attribute if: (1) it is too busy to return
events, (2) the Notification Recipient client did not request
Event Wait Mode, or (3) the Printer is terminating Event Wait
Mode. The client MUST accept this attribute and SHOULD re-
issue the Get-Notifications operation (with or without "notify-
wait" = 'true') the indicated number of seconds in the future
in order to get more Event Notifications This value is
intended to help the client be a good network citizen.
The value of this attribute MUST be at least as large as the
value of the Printer's "ippget-event-life" Printer Description
attribute (see section 8.1). The Printer MAY return a value
that is larger than the value of the "ippget-event-life"
Printer Description attribute provided that the Printer
increases the Event Life for this Subscription object, so that
Notification Recipients taking account of the larger value and
polling with a longer interval will not miss events. Note;
implementing such an algorithm requires some hidden attributes
in the Subscription object that are IMPLEMENTATION DEPENDENT.
If the Printer wants to remain in Event Wait Mode, then the
Printer MUST NOT return this attribute in the response.
Here is a complete table of combinations of "notify-wait",
"status-code", "notify-get-interval", and Event Notification
Attributes Groups for Get-Notification initial (Wait and No
Wait) Responses and subsequent Event Wait Mode Responses (which
may be staying in Event Wait Mode or may be requesting the
Notification Recipient to leave Event Wait Mode):
Table 2 - Combinations of "notify-wait", "status-code", and "notify-
get-interval"
client sends: Printer Event
returns: returns: Notification
"notify-wait" "status-code" "notify-get- Attribute
interval" Groups
1. 'successful- MUST return N maybe
'false'/omitte ok'
d
2. 'not-found' MUST NOT MUST NOT
'false'/omitte
d
3. 'busy' MUST return N MUST NOT
'false'/omitte
d
4. 'events- MUST NOT 'job-
'false'/omitte complete' completed'
d
5. 'true' 'successful- MUST NOT MUST
ok'
6. 'true' 'successful- MUST return N maybe
ok'
7. 'true' 'not-found' MUST NOT MUST NOT
8. 'true' 'busy' MUST return N MUST NOT
9. 'true' 'events- MUST NOT 'job-
complete' completed' or
maybe other
Explanation:
1-4: client does not request Event Wait Mode
5-9: client requests Event Wait Mode
2,7: Subscription object not found, or was canceled earlier;
client should NOT try again.
3,8: server busy, tells client to try later; client should try
again in N seconds.
4: client polled after job completed, but before Event Life
expired, and got the 'job-completed' event, so the client
shouldn't bother trying again; client should NOT try again
later.
5: Printer returns one or more Event Notifications and is OK
to stay in Event Wait Mode; the client waits for more Event
Notifications to be returned.
6: Printer wants to leave Event Wait mode. Can happen on the
first response (with or without Event Notifications) or happen
on a subsequent response with or without Event Notifications;
the client SHOULD try again in N seconds.
9: Printer either (1) returns 'job-completed' event or (2) the
Subscription Object was canceled by either a Cancel-Job or a
Per-Printer Subscription expired without being renewed. For
case (1), at least one Event Notification MUST be returned,
while for case (2), it is unlikely that any Event Notifications
are returned; the client should NOT try again.
5.2.2 "printer-up-time" (integer(1:MAX)):
The value of this attribute is the Printer's "printer-up-time" The value of this attribute is the Printer's "printer-up-time"
attribute at the time the Printer sends this response. Because attribute at the time the Printer sends this response. The
each Event Notification also contains the value of this Printer MUST return this attribute. Because each Event
attribute when the event occurred, the value of this attribute Notification also contains the value of this attribute when the
lets a Notification Recipient know when each Event Notification event occurred, the value of this attribute lets a Notification
occurred relative to the time of this response. Recipient know when each Event Notification occurred relative
to the time of this response.
5.2.3 "redirect-uri" (uri):
"redirect-uri" (uri):
The value of this attribute is the uri that the Notification The value of this attribute is the uri that the Notification
Recipient MUST use for a subsequent Get-Notifications Recipient MUST use for a subsequent Get-Notifications
operation. This attribute is returned in the Operation operation. The Printer MAY support this attribute. This
Attributes Group if and only if the status code has the value attribute MUST be returned in the Operation Attributes Group if
'redirection-other-site'. and only if the Printer returns the 'redirection-other-site'
status code (see section 10.2).
Group 2: Unsupported Attributes Group 2: Unsupported Attributes
See [RFC2911] section 3.1.7 for details on returning See [RFC2911] section 3.1.7 for details on returning
Unsupported Attributes. Unsupported Attributes.
Group 3 through N: Event Notification Attributes Group 3 through N: Event Notification Attributes
The Printer responds with one Event Notification Attributes The Printer responds with one Event Notification Attributes
Group per matched Event Notification. The entire response is Group per matched Event Notification. The entire response is
considered a single Compound Event Notification (see [ipp- considered a single Compound Event Notification (see [ipp-
ntfy]). The last Event Notification Attributes Group MAY ntfy]). The matched Event Notifications are all un-expired
contain a single "notify-get-interval" (see section 7.1 and
12), in which case the Printer will return no future responses.
The initial matched Event Notifications are all un-expired
Event Notification associated with the matched Subscription Event Notification associated with the matched Subscription
Objects and MUST follow the "Event Notification Ordering" Objects and MUST follow the "Event Notification Ordering"
requirements for Event Notifications within a Compound Event requirements for Event Notifications within a Compound Event
Notification specified in [ipp-ntfy] section 9. Notification specified in [ipp-ntfy] section 9. In other
words, the Printer MUST order these Event Notification groups
If the Notification Recipient has selected the Event Wait Mode in ascending time stamp (and sequence number) order for a
option to wait for additional Event Notifications (the "notify- Subscription object. If Event Notifications for multiple
wait" attribute was set to 'true'), the Printer sends Subscription objects are being returned, the Notification
subsequent Event Notifications in the response each time it Events for the next Subscription object follow in ascending
processes additional Events. Each time the Printer sends such time stamp order, etc.
Event Notifications, their ordering MUST follow the "Event
Notification Ordering" requirements in [ipp-ntfy] section 9.
Note: If a Notification Recipient performs two consecutive Get-
Notifications operations, the time stamp of the first Event
Notification in the second Get-Notifications Response may be
less than the time stamp of the last Event Notification in the
first Get-Notification Response. This happens because the
Printer sends all unexpired Event Notification according to the
ordering specified in [ipp-ntfy] and some Event Notifications
from the first Get-Notifications operation may not have expired
by the time the second Get-Notifications operation occurs.
From the Notification Recipient's view, the response appears as
an initial burst of data, which includes the Operation
Attributes Group and one Event Notification Attributes Group
per Event Notification that the Printer is holding. After the
initial burst of data, if the Notification Recipient has
selected the Event Wait Mode option to wait for additional
Event Notifications, the Notification Recipient receives
occasional Event Notification Attribute Groups. Proxy servers
may delay some Event Notifications or cause time-outs to occur.
The client MUST be prepared to perform the Get-Notifications
operation again when time-outs occur.
Each attribute is encoded using the IPP rules for encoding
attributes [RFC2910] and MAY be encoded in any order. Note:
the Get-Jobs response in [RFC2911] acts as a model for encoding
multiple groups of attributes. See section 12 for the encoding
and transport rules.
Each Event Notification Group MUST contain all of attributes Each Event Notification Group MUST contain all of attributes
specified in section 9.1 ("Content of Machine Consumable Event specified in section 9.1 ("Content of Machine Consumable Event
Notifications") of [ipp-ntfy] with exceptions denoted by Notifications") of [ipp-ntfy] with exceptions denoted by
asterisks in the tables below. asterisks in the tables below.
The tables below are copies of the tables in section 9.1 The tables below are copies of the tables in section 9.1
("Content of Machine Consumable Event Notifications") of [ipp- ("Content of Machine Consumable Event Notifications") of [ipp-
ntfy] except that each cell in the "Sends" column is a "MUST". ntfy] except that each cell in the "Sends" column is a "MUST".
If more than one Event Notification is being returned and the
status of each is not the same, then the Printer MUST return a
"notify-status-code" attribute in each Event Notification
Attributes group to indicate the differing status values.
For an Event Notification for all Events, the Printer includes For an Event Notification for all Events, the Printer includes
the attributes shown in Table 2. the attributes shown in Table 3.
Table 2 " Attributes in Event Notification Content Table 3 - Attributes in Event Notification Content
Source Value Sends Source Object Source Value Sends Source
Object
notify-subscription-id (integer(1:MAX)) MUST Subscription notify-subscription-id (integer(1:MAX)) MUST Subscription
notify-printer-uri (uri) MUST Subscription notify-printer-uri (uri) MUST Subscription
notify-subscribed-event (type2 keyword) MUST Event notify-subscribed-event (type2 keyword) MUST Event
Notification Notification
printer-up-time (integer(1:MAX)) MUST Printer
printer-current-time (dateTime) MUST * Printer printer-up-time (integer(1:MAX)) * MUST Printer
printer-current-time (dateTime) MUST ** Printer
notify-sequence-number (integer (0:MAX)) MUST Subscription notify-sequence-number (integer (0:MAX)) MUST Subscription
notify-charset (charset) MUST Subscription notify-charset (charset) MUST Subscription
notify-natural-language (naturalLanguage) MUST Subscription notify-natural-language (naturalLanguage) MUST Subscription
notify-user-data (octetString(63)) MUST ** Subscription
notify-user-data (octetString(63)) MUST *** Subscription
notify-text (text) MUST Event notify-text (text) MUST Event
Notification Notification
attributes from the "notify-attributes" MUST *** Printer
attributes from the "notify-attributes" MUST **** Printer
attribute attribute
attributes from the "notify-attributes" MUST *** Job
attributes from the "notify-attributes" MUST **** Job
attribute attribute
attributes from the "notify-attributes" MUST *** Subscription
attributes from the "notify-attributes" MUST **** Subscription
attribute attribute
* The Printer MUST send the "printer-current-time" attribute if * As specified in [ipp-ntfy] section 9, the value of the
and only if it supports the "printer-current-time" attribute on "printer-up-time" attribute sent in each Event Notification
the Printer object. MUST be the time at which the Event occurred, not the time at
which the Event Notification was sent.
** If the associated Subscription Object does not contain a ** The Printer MUST send the "printer-current-time" attribute
if and only if it supports the "printer-current-time" attribute
on the Printer object.
*** If the associated Subscription Object does not contain a
"notify-user-data" attribute, the Printer MUST send an octet- "notify-user-data" attribute, the Printer MUST send an octet-
string of length 0. string of length 0.
*** If the "notify-attributes" attribute is present on the **** If the "notify-attributes" attribute is present on the
Subscription Object, the Printer MUST send all attributes Subscription Object, the Printer MUST send all attributes
specified by the "notify-attributes" attribute. Note: if the specified by the "notify-attributes" attribute. Note: if the
Printer doesn't support the "notify-attributes" attribute, it Printer doesn't support the "notify-attributes" attribute, it
is not present on the associated Subscription Object. is not present on the associated Subscription Object.
For Event Notifications for Job Events, the Printer includes For Event Notifications for Job Events, the Printer includes
the additional attributes shown in Table 3. the additional attributes shown in Table 4.
Table 3 " Additional Attributes in Event Notification Content for Table 4 - Additional Attributes in Event Notification Content for
Job Events Job Events
Source Value Sends Source Source Value Sends Source
Object Object
job-id (integer(1:MAX)) MUST Job job-id (integer(1:MAX)) MUST Job
job-state (type1 enum) MUST Job job-state (type1 enum) MUST Job
job-state-reasons (1setOf type2 keyword) MUST Job job-state-reasons (1setOf type2 keyword) MUST Job
job-impressions-completed (integer(0:MAX)) MUST * Job job-impressions-completed (integer(0:MAX)) MUST * Job
* The Printer MUST send the "job-impressions-completed" * The Printer MUST send the "job-impressions-completed"
attribute in an Event Notification only for the combinations of attribute in an Event Notification only for the combinations of
Events and Subscribed Events shown in Table 4. Events and Subscribed Events shown in Table 5.
Table 4 " Combinations of Events and Subscribed Events for "job- Table 5 - Combinations of Events and Subscribed Events for "job-
impressions-completed" impressions-completed"
Job Event Subscribed Job Event Job Event Subscribed Job Event
'job-progress' 'job-progress' 'job-progress' 'job-progress'
'job-completed' 'job-completed' 'job-completed' 'job-completed'
'job-completed' 'job-state-changed' 'job-completed' 'job-state-changed'
For Event Notification for Printer Events, the Printer includes For Event Notification for Printer Events, the Printer includes
the additional attributes shown in Table 5. the additional attributes shown in Table 6.
Table 5 " Additional Attributes in Event Notification Content for Table 6 - Additional Attributes in Event Notification Content for
Printer Events Printer Events
Source Value Sends Source Source Value Sends Source
Object Object
printer-state (type1 enum) MUST Printer printer-state (type1 enum) MUST Printer
printer-state-reasons (1setOf type2 keyword) MUST Printer
printer-is-accepting-jobs (boolean) MUST Printer
6 Subscription Template Attributes
This section defines the Subscription object conformance requirements
for Printers.
6.1 Subscription Template Attribute Conformance printer-state-reasons (1setOf type2 keyword) MUST Printer
The 'ippget' Delivery Method has the same conformance requirements printer-is-accepting-jobs (boolean) MUST Printer
for Subscription Template attributes as defined in [ipp-ntfy]. The
'ippget' Delivery Method does not define any addition Subscription
Template attributes.
6.2 Additional Information about Subscription Template Attributes 6 Additional Information about Subscription Template Attributes
This section defines additional information about Subscription The 'ippget' Delivery Method does not define any addition
Template attributes defined in [ipp-ntfy]. Subscription Template attributes. The 'ippget' Delivery Method has
the same conformance requirements for Subscription Template
attributes as defined in [ipp-ntfy]. This section defines additional
information about Subscription Template attributes defined in [ipp-
ntfy].
6.2.1 notify-recipient-uri (uri) 6.1 notify-recipient-uri (uri)
This section describes the syntax of the value of this attribute for This section describes the syntax of the value of this attribute for
the 'ippget' Delivery Method. The syntax for values of this the 'ippget' Delivery Method. The syntax for values of this
attribute for other Delivery Method is defined in other Delivery attribute for other Delivery Method is defined in other Delivery
Method Documents. Method Documents.
In order to support the 'ippget' Delivery Method and Protocol, the In order to support the 'ippget' Delivery Method and Protocol, the
Printer MUST support the following syntax: Printer MUST support the following syntax:
The 'ippget://' URI scheme. The remainder of the URI indicates The 'ippget://' URI scheme. The remainder of the URI indicates
something unique about the Notification Recipient, such as its host something unique about the Notification Recipient, such as its host
name or host address (and optional path) that the Printer uses to name or host address (and optional path). However, the remainder
match the "notify-recipient-uri" Operation attribute supplied in of the URI is not used by the Printer in any way. Its value MAY be
the Get-Notifications request. See section 11 for a complete useful to Notification Recipients who are not the Subscription
definition of the syntax of the IPPGET URL. Creation clients. See section 11 for a complete definition of the
syntax of the IPPGET URL.
6.3 Subscription Description Attribute Conformance 7 Subscription Description Attributes
The 'ippget' Delivery Method has the same conformance requirements The 'ippget' Delivery Method has the same conformance requirements
for Subscription Description attributes as defined in [ipp-ntfy]. for Subscription Description attributes as defined in [ipp-ntfy].
The 'ippget' Delivery Method does not define any addition The 'ippget' Delivery Method does not define any addition
Subscription Description attributes. Subscription Description attributes.
7 Attributes only in Event Notifications
This section defines attributes that exist only in Event
Notifications and do no exist in any IPP-defined objects.
7.1 "notify-get-interval" (integer(0:MAX))
The Printer returns this attribute to give the client an indication
of when to try another Get-Notifications request in the future. The
value of this attribute is the number of seconds that the
Notification Recipient SHOULD wait before trying the Get-
Notifications operation again. This value is intended to help the
client be a good network citizen.
The Printer MUST return this attribute by itself in a separate Event
Notification Attributes Group. The Printer MUST return this
attribute if and only if:
1. Printer busy case: the Printer returns the 'server-error-busy'
status code OR
2. No wait case: the Printer returns the 'successful-ok' status
code and the client either (1) supplied the "notify-wait"
attribute with a value of 'false' or (2) omitted the attribute
entirely OR
3. Printer leaves Event Wait Mode: the Printer returns the
'successful-ok' status code and the client supplied the "notify-
wait" attribute with the 'true value (Event Wait Mode) but the
Printer wants the client to disconnect (no wait), instead of
staying connected. The client MUST accept this response and
MUST disconnect. If the client does not disconnect, the Printer
SHOULD do so. The Printer returns this attribute for this case
only if the implementation does not want to keep the connection
open at this time. If the Printer wants the client to keep the
connection open and remain in Event Wait Mode, then the Printer
MUST NOT return this attribute in the response.
8 Additional Printer Description Attributes 8 Additional Printer Description Attributes
This section defines additional Printer Description attributes for This section defines additional Printer Description attributes for
use with the 'ippget' Delivery Method. use with the 'ippget' Delivery Method.
8.1 ippget-event-time-to-live (integer(0:MAX)) 8.1 ippget-event-life (integer(15:MAX))
This Printer Description attribute specifies the number of seconds This Printer Description attribute specifies the Event Life value
that a Printer keeps an Event Notification that is associated with that the Printer assigns to each Event, i.e., the number of seconds
the 'ippget' Delivery Method. after an Event occurs during which a Printer will return that Event
in an Event Notification in a Get-Notifications response. After the
Event Life expires for the Event, the Printer MAY no longer return an
Event Notification for that Event in a Get-Notifications response.
The Printer MUST support this attribute if it supports the 'ippget' The Printer MUST support this attribute if it supports the 'ippget'
Delivery Method. Delivery Method. The value MUST be 15 or more (at least 15 seconds)
and 60 (seconds) is the RECOMMENDED value to align with the PWG Job
The value of this attribute is the minimum number of seconds that Monitoring MIB [RFC2707] jmGeneralJobPersistence and
MUST elapse between the time the Printer creates an Event jmGeneralAttributePersistence objects.
Notification object for the 'ippget' Delivery Method and the time the
Printer discards the same Event Notification.
For example, assume the following: For example, assume the following:
1. a client performs a Job Creation operation that creates a 1. a client performs a Job Creation operation that creates a
Subscription Object associated with this Delivery Method, AND Subscription Object associated with the 'ippget' Delivery
Method, AND
2. an Event associated with the new Job occurs immediately after 2. an Event associated with the new Job occurs immediately after
the Subscription Object is created, AND the Subscription Object is created, AND
3. the same client or some other client performs a Get- 3. the same client or some other client performs a Get-
Notifications operation N seconds after the Job Creation Notifications operation such that the client is connected N
operation. seconds after the Job Creation operation.
Then, if N is less than the value of this attribute, the client(s) Then, if N is less than the value of this attribute, the client(s)
performing the Get-Notifications operations can expect not to miss performing the Get-Notifications operations can expect not to miss
any Event-Notifications, barring some unforeseen lack of memory space any Event-Notifications, barring some unforeseen lack of memory space
in the Printer. in the Printer. Note: The client MUST initiate the Get-
Notifications a time that is sufficiently less that N seconds to
account for network latency so that it is connected to the Printer
before N seconds elapses.
The value of this attribute also specifies the minimum number of If a Printer supports the 'ippget' Delivery Method, it MUST keep
seconds that the Printer, if supporting the ippget Delivery Method, 'completed', 'canceled', or 'aborted' Job objects in the Job
MUST keep 'completed', 'canceled', or 'aborted' Job objects in the Retention and/or Job History phases for at least as long as this
Job Retention and/or Job History phases. See [RFC2911] section attribute's value. The Printer MAY retain jobs longer that this
4.3.7.1 and the discussion in [ipp-ntfy] 'job-completed' event) that value. See [RFC2911] section 4.3.7.1 and the discussion in [ipp-
explains that a Notification Recipients can query the Job after ntfy] 'job-completed' event) that explains that a Notification
receiving a 'job-completed' Event Notification in order to find out Recipients can query the Job after receiving a 'job-completed' Event
other information about the job that is completing. However, this Notification in order to find out other information about the job
that is 'completed', 'aborted', or 'canceled'. However, this
attribute has no effect on the Cancel-Subscription operation which attribute has no effect on the Cancel-Subscription operation which
deletes the object immediately, whether or not it contain the ippget deletes the Subscription object immediately, whether or not it
scheme. Immediately thereafter, subsequent Get-Notifications contain the 'ippget' scheme. Immediately thereafter, subsequent Get-
Responses MUST NOT contain Event Notifications associated with the Notifications Responses MUST NOT contain Event Notifications
cancelled Subscription object. associated with the canceled Subscription object.
9 New Values for Existing Printer Description Attributes 9 New Values for Existing Printer Description Attributes
This section defines additional values for existing Printer This section defines additional values for existing Printer
Description attributes define in [ipp-ntfy]. Description attributes defined in [ipp-ntfy].
9.1 notify-schemes-supported (1setOf uriScheme) 9.1 notify-schemes-supported (1setOf uriScheme)
The following value for the "notify-schemes-supported" attribute is The following value for the "notify-schemes-supported" attribute is
added in order to support the new Delivery Method defined in this added in order to support the new Delivery Method defined in this
document: document:
'ippget' - The IPP Notification Delivery Method defined in this 'ippget' - The IPP Notification Delivery Method defined in this
document. document.
9.2 operations-supported (1setOf type2 enum) 9.2 operations-supported (1setOf type2 enum)
Table 6 lists the "operation-id" value defined in order to support Table 7 lists the "operation-id" value defined in order to support
the new Get-Notifications operation defined in this document. the new Get-Notifications operation defined in this document.
Table 6 " Operation-id assignments Table 7 - Operation-id assignments
Value Operation Name Value Operation Name
0x001C Get-Notifications 0x001C Get-Notifications
10 New Status Codes 10 New Status Codes
The following status codes are defined as extensions for this The following status codes are defined as extensions for this
Delivery Method and are returned as the status code of the Get- Delivery Method and are returned as the status code of the Get-
Notifications operation. Notifications operation.
10.1 redirection-other-site (0x0300) 10.1 successful-ok-events-complete (0x0007)
The Printer MUST return the 'successful-ok-events-complete' status
code to indicate when this Get-Notifications response is the last
response for a Subscription object, whether or not there are Event
Notifications being returned. This condition occurs for Event Wait
Mode with Notification Recipients waiting for responses when the
Subscription Object is: (1) canceled with a Cancel-Subscription
operation, (2) deleted when the Per-Printer Subscription lease time
expires, or (3) when the 'job-completed' event occurs for a Per-Job
Subscription. This condition also occurs for a Get-Notifications
request that a Notification Recipient makes after the job completes,
but before the Event Life expires.
10.2 redirection-other-site (0x0300)
This status code means that the Printer doesn't perform that Get- This status code means that the Printer doesn't perform that Get-
Notifications operation and that the "redirect-uri" Operation Notifications operation and that the "redirect-uri" operation
Attribute in the response contains the uri that the Notification attribute in the response contains the uri that the Notification
Recipient MUST use for performing the Get-Notifications operation. Recipient MUST use for performing the Get-Notifications operation.
If the client issues subsequent Get-Notifications operations, it MUST
use the value of the "redirect-uri" operation attribute returned by
the Printer as the target of the operation.
11 The IPPGET URL Scheme 11 The IPPGET URL Scheme
This section defines the 'ippget' URL and the conformance This section defines the 'ippget' URL and the conformance
requirements for using it. requirements for using it.
11.1 The IPPGET URL Scheme Applicability and Intended Usage 11.1 The IPPGET URL Scheme Applicability and Intended Usage
This section is intended for use in registering the 'ippget' URL This section is intended for use in registering the 'ippget' URL
scheme with IANA and fully conforms to the requirements in [RFC2717]. scheme with IANA and fully conforms to the requirements in [RFC2717].
This document defines the 'ippget'" URL (Uniform Resource Locator) This document defines the 'ippget'" URL (Uniform Resource Locator)
scheme for specifying a unique identifier for an IPP Client which scheme for specifying a unique identifier for an IPP Client which
implements the IPP Get-Notifications operation specified in this implements the IPP Get-Notifications operation specified in this
document (see section 5). document (see section 5).
ISSUE 02: How unique do we need now that the Printer doesn't use
anything but the scheme?
The intended usage of the 'ippget' URL scheme is COMMON. The intended usage of the 'ippget' URL scheme is COMMON.
11.2 The IPPGET URL Scheme Associated Port 11.2 The IPPGET URL Scheme Associated Port
None. None.
An 'ippget' URL behaves as a unique identifier for IPP Clients and is An 'ippget' URL behaves as a unique identifier for IPP Clients and is
NOT used to initiate any over-the-wire protocol associations. NOT used to initiate any over-the-wire protocol associations.
See: IANA Port Numbers Registry [IANA-PORTREG]. See: IANA Port Numbers Registry [IANA-PORTREG].
11.3 The IPPGET URL Scheme Associated MIME Type 11.3 The IPPGET URL Scheme Associated MIME Type
All IPP Get-Notifications operations (requests and responses) MUST be All IPP Get-Notifications operations (requests and responses) MUST be
conveyed in an 'application/ipp' MIME media type as registered in conveyed in an 'application/ipp' MIME media type as registered in
[IANA-MIMEREG]. An 'ippget' URL MUST uniquely identify an IPP Client [IANA-MT]. An 'ippget' URL MUST uniquely identify an IPP Client that
that support this 'application/ipp' MIME media type. support this 'application/ipp' MIME media type.
See: IANA MIME Media Types Registry [IANA-MIMEREG]. See: IANA MIME Media Types Registry [IANA-MT].
11.4 The IPPGET URL Scheme Character Encoding 11.4 The IPPGET URL Scheme Character Encoding
The 'ippget' URL scheme defined in this document is based on the ABNF The 'ippget' URL scheme defined in this document is based on the ABNF
for the URI Generic Syntax [RFC2396] and further updated by [RFC2732] for the URI Generic Syntax [RFC2396] and further updated by [RFC2732]
and [RFC2373] (for IPv6 addresses in URLs). The 'ippget' URL scheme and [RFC2373] (for IPv6 addresses in URLs). The 'ippget' URL scheme
is case-insensitive in the scheme and 'authority' part; however, the is case-insensitive in the scheme and 'authority' part as in
'abs_path' part is case-sensitive, as in [RFC2396]. Code points [RFC2396]; however, the 'abs_path' part is case-sensitive, as in
outside [US-ASCII] MUST be hex escaped by the mechanism specified in [RFC2396]. Code points outside [US-ASCII] MUST be hex escaped by the
[RFC2396]. mechanism specified in [RFC2396].
11.5 The IPPGET URL Scheme Syntax in ABNF 11.5 The IPPGET URL Scheme Syntax in ABNF
This document is intended for use in registering the 'ippget' URL This document is intended for use in registering the 'ippget' URL
scheme with IANA and fully conforms to the requirements in [RFC2717]. scheme with IANA and fully conforms to the requirements in [RFC2717].
This document defines the 'ippget' URL (Uniform Resource Locator) This document defines the 'ippget' URL (Uniform Resource Locator)
scheme for specifying a unique identifier for an IPP Client which scheme for specifying a unique identifier for an IPP Client which
implements IPP 'Get-Notifications' operation specified in this implements IPP 'Get-Notifications' operation specified in this
document. document.
The intended usage of the 'ippget' URL scheme is COMMON. The intended usage of the 'ippget' URL scheme is COMMON.
The IPP protocol places a limit of 1023 octets (NOT characters) on The value of an 'ippget' URI MUST NOT exceed 255 octets (see section
the length of a URI (see section 4.1.5 'uri' in [RFC2911]). An IPP 8.1), since the URI is for identification rather than for identifying
Printer MUST return the 'client-error-request-value-too-long' status the location of a network resource. An IPP Printer MUST return the
code (see section 13.1.4.10 in [RFC2911]) when a URI received in a 'client-error-request-value-too-long' status code (see section
request is too long. 13.1.4.10 in [RFC2911]) when a URI received in a request is too long.
Note: IPP Clients and IPP Printers ought to be cautious about
depending on URI lengths above 255 bytes, because some older client
or proxy implementations might not properly support these lengths.
An 'ippget' URL MUST be represented in absolute form. Absolute URLs An 'ippget' URL MUST be represented in absolute form. Absolute URLs
always begin with a scheme name followed by a colon. For definitive always begin with a scheme name followed by a colon. For definitive
information on URL syntax and semantics, see "Uniform Resource information on URL syntax and semantics, see "Uniform Resource
Identifiers (URI): Generic Syntax and Semantics" [RFC2396]. This Identifiers (URI): Generic Syntax and Semantics" [RFC2396]. This
specification adopts the definitions of "authority", "abs_path", specification adopts the definitions of "authority", "abs_path",
"query", "reg_name", "server", "userinfo", and "hostport" from "query", "reg_name", "server", "userinfo", and "hostport" from
[RFC2396], as updated by [RFC2732] and [RFC2373] (for IPv6 addresses [RFC2396], as updated by [RFC2732] and [RFC2373] (for IPv6 addresses
in URLs). in URLs).
skipping to change at page 24, line 15 skipping to change at page 29, line 19
Note: The use of IP addresses in URLs SHOULD be avoided whenever Note: The use of IP addresses in URLs SHOULD be avoided whenever
possible (see [RFC1900]). possible (see [RFC1900]).
11.5.1 IPPGET URL Examples 11.5.1 IPPGET URL Examples
The following are examples of valid 'ippget' URLs for IPP Clients The following are examples of valid 'ippget' URLs for IPP Clients
(using DNS host names): (using DNS host names):
ippget://abc.com ippget://abc.com
ippget://abc.com/listener ippget://abc.com/listener
ippget://bob@abc.com
ippget://bob@abc.com/listener/1232 ippget://bob@abc.com/listener/1232
Note: The use of IP addresses in URLs SHOULD be avoided whenever Note: The use of IP addresses in URLs SHOULD be avoided whenever
possible (see [RFC1900]). possible (see [RFC1900]).
The IPP Client that creates the Subscription object and the The IPP Client that creates the Subscription object and the
Notification Recipient have to agree on a unique IPPGET URL value in Notification Recipient have to agree on a unique IPPGET URL value in
order for the Get-Notifications operations to retrieve the proper order for the Get-Notifications operations to retrieve the proper
Event Notifications. Therefore, the choice of 'userinfo@hostport' Event Notifications. Therefore, the choice of 'userinfo@hostport'
versus the simpler 'hostport' production in an 'ippget' URL may be versus the simpler 'hostport' production in an 'ippget' URL may be
skipping to change at page 24, line 43 skipping to change at page 30, line 7
On the other hand, if a given IPP Client creates an IPP Subscription On the other hand, if a given IPP Client creates an IPP Subscription
object for event notifications intended for retrieval by a different object for event notifications intended for retrieval by a different
IPP Client, then the 'userinfo@hostport' production (using, for IPP Client, then the 'userinfo@hostport' production (using, for
example, the right-hand side of a 'mailto:' URL, see [RFC2368]) may example, the right-hand side of a 'mailto:' URL, see [RFC2368]) may
be most appropriate. For this case, a mail address serves as the be most appropriate. For this case, a mail address serves as the
prior agreement on the IPPGET URL value between the IPP Client and prior agreement on the IPPGET URL value between the IPP Client and
the Notification Recipient. the Notification Recipient.
11.5.2 IPPGET URL Comparisons 11.5.2 IPPGET URL Comparisons
When comparing two 'ippget' URLs to decide if they match or not, When comparing two 'ippget' URLs to decide if they match or not, an
an IPP Client or IPP Printer MUST use the same rules as those IPP Client or IPP Printer MUST use the same rules as those defined
defined for HTTP URI comparisons in [RFC2616]. for HTTP URI comparisons in [RFC2616].
12 Encoding and Transport 12 Encoding and Transport
This section defines the encoding and transport considerations for This section defines the encoding and transport considerations for
this Delivery Method based on [RFC2910]. this Delivery Method based on [RFC2910].
The encoding of a Get-Notifications Response is modeled the Get-Jobs The encoding of a Get-Notifications Response is modeled the Get-Jobs
Response (see [RFC2911]). In a Get-Notifications Response, each Response (see [RFC2911]). In a Get-Notifications Response, each
Event Notification Attributes Group MUST start with an 'event- Event Notification Attributes Group MUST start with an 'event-
notification-attributes-tag' (see the section "Encodings of notification-attributes-tag' (see the section "Encodings of
Additional Attribute Tags" in [ipp-ntfy]), but only the last group Additional Attribute Tags" in [ipp-ntfy]), and end with an 'end-of-
ends with an 'end-of-attributes-tag'. In addition, for Event Wait attributes-tag'. In addition, for Event Wait Mode the multi-
Mode the multi-part/related is used to separate each multiple part/related is used to separate each multiple response (in time) to
response (in time) to a single Get-Notifications Request. a single Get-Notifications Request.
The Printer returns Get-Notification Response as follows: The Printer returns Get-Notification Response as follows:
1. If the Notification Recipient client did not request Event Wait 1. If the Notification Recipient client did not request Event Wait
Mode ("notify-wait" = 'false' or omitted), the Printer ends the Mode ("notify-wait" = 'false' or omitted), the Printer ends the
response with an 'end-of-attributes-tag' (see [RFC2911] Get-Jobs response with an 'end-of-attributes-tag' (see [RFC2911] Get-Jobs
encoding) as with any operation response. The Notification encoding) as with any operation response.
Recipient is expected to close the connection.
2. If the Notification Recipient client requests Event Wait Mode 2. If the Notification Recipient client requests Event Wait Mode
("notify-wait" = 'true') and the Printer wishes to honor the ("notify-wait" = 'true') and the Printer wishes to honor the
request, the Printer ends the Response without an 'end-of- request, the Printer MUST return the response as an
attributes-tag' and MUST return the response as an
application/ipp part inside a multi-part/related MIME media application/ipp part inside a multi-part/related MIME media
type. Neither the Notification Recipient nor the Printer close type. When one or more additional Events occur, the Printer
the connection. When one or more additional Events occur, the returns each as an additional Event Notification Group using a
Printer returns each as an additional Event Notification Group separate application/ipp part under the multi-part/related type.
using a separate application/ipp part under the multi-
part/related type.
3. If the client requested Event Wait Mode ("notify-wait" = 3. If the client requested Event Wait Mode ("notify-wait" =
'true'), but the Printer does not wish to honor the request in 'true'), but the Printer does not wish to honor the request in
the initial response but wants the client to disconnect, the the initial response but wants the client explicitly poll for
Printer MUST return the "notify-get-interval" attribute (see Event Notifications, the Printer MUST return the "notify-get-
section 7.1) as the last Event Notifications Attributes Group - interval" operation attribute (see section 5.2.1). The Printer
see section 5.2), the Printer ends the Response with an 'end-of- returns the response as an application/ipp part which MAY be
attributes-tag'. The Printer returns the response as an inside an multi-part/related type. The client MUST accept this
application/ipp part which MAY be inside an multi-part/related response and re-issue the Get-Notifications request in the
type. The client MUST accept this response and MUST disconnect. future indicated by the value of the "notify-get-interval"
If the client does not disconnect, the Printer SHOULD do so. attribute value..
4. If the client requested Event Wait Mode ("notify-wait" = 4. If the client requested Event Wait Mode ("notify-wait" =
'true'), and the Printer initially honored the request, but 'true'), and the Printer initially honored the request, but
later wishes to leave Event Wait Mode, the Printer MUST return later wishes to leave Event Wait Mode, the Printer MUST return
the "notify-get-interval" attribute (see section 7.1) as the the "notify-get-interval" operation attribute (see section
last Event Notifications Attributes Group - see section 5.2), 5.2.1). The Printer returns the response as an application/ipp
the Printer ends the Response with an 'end-of-attributes-tag'. part which MUST be inside an multi-part/related type.
The Printer returns the response as an application/ipp part
which MUST be inside an multi-part/related type.
ISSUE: Should we use application/multiplexed (draft-herriot-
application-multiplexed-03.txt) which can chunk mime types using
content lengths, instead of multi-part/related, which uses boundary
strings?
Note: either the Notification Recipient or the Printer can abnormally Note: All of the above is without either the Printer or the
terminate by closing the connection. However, if the Printer closes Notification Recipient closing the connection. In fact, the
the connection too soon after returning the response, the client may connection SHOULD remain open for any subsequent IPP operations.
not receive the response. However, either the Notification Recipient or the Printer can
abnormally terminate by closing the connection. But, if the Printer
closes the connection too soon after returning the response, the
client may not receive the response.
The Printer MAY chunk the responses, but this has no significance to The Printer MAY chunk the responses, but this has no significance to
the IPP semantics. the IPP semantics.
Note: While HTTP/1.1 allows a proxy to collect chunked responses
over a period of time and return them back as a single un-chunked
response (with a Content Length instead). However, in practice no
proxy wants to have an infinite buffer. Also no proxy want to hold
up responses, since user would be furious.
This notification delivery method uses the IPP transport and encoding This notification delivery method uses the IPP transport and encoding
[RFC2910] for the Get-Notifications operation with one extension [RFC2910] for the Get-Notifications operation with the following
allocated in [ipp-ntfy]: extension allocated in [ipp-ntfy]:
Table 7 " The "event-notification-attributes-tag" value Table 8 - The "event-notification-attributes-tag" value
Tag Value (Hex) Meaning Tag Value (Hex) Meaning
0x07 "event-notification-attributes-tag" 0x07 "event-notification-attributes-tag"
13 Conformance Requirements 13 Conformance Requirements
The 'ippget' Delivery Method is RECOMMEND for Printers to support. The 'ippget' Delivery Method is RECOMMEND for Printers to support.
13.1 Conformance for IPP Printers 13.1 Conformance for IPP Printers
IPP Printers that conform to this specification: IPP Printers that conform to this specification:
1. MUST meet the conformance requirements defined in [ipp-ntfy]; 1. MUST meet the conformance requirements defined in [ipp-ntfy];
2. MUST support the Get-Notifications operation defined in section 2. MUST support the Get-Notifications operation defined in section
5; 5, including Event Wait Mode;
3. MUST support the Subscription object attributes as defined in 3. MUST support the Subscription Template object attributes as
section 6; defined in section 6;
4. MUST support the additional values for IPP/1.1 Printer
Description attributes defined in section 9;
#@# next line is > 72 characters: 73 4. MUST support the Subscription Description object attributes as
5. MUST support the "ippget-event-time-to-live" Printer Description defined in section 7;
attribute defined in section 8.1;
6. MUST support the "redirection-other-site" status code defined 5. MUST support the "ippget-event-life" Printer Description
10.1, if it redirects Get-Notifications operations; attribute defined in section 8.1, including retaining jobs in
the Job Retention and/or Job History phases for at least as long
as the value specified by the Printer's "ippget-event-life";
7. SHOULD reject received 'ippget' URLs in 'application/ipp' 6. MUST support the additional values for IPP/1.1 Printer
request bodies (e.g., in the "notify-recipient-uri" attribute in Description attributes defined in section 9;
a Get-Notifications request) that do not conform to the ABNF for
'ippget' URLs specified in section 11.5 of this document;
8. MUST listen for the IPP Get-Notifications operation requests on 7. MUST support the 'successful-ok-events-complete' status code as
described in section 10.1;
8. MUST support the "redirection-other-site" status code defined
10.2, if it redirects Get-Notifications operations;
9. MUST listen for the IPP Get-Notifications operation requests on
IANA-assigned well-known port 631, unless explicitly configured IANA-assigned well-known port 631, unless explicitly configured
by system administrators or site policies; by system administrators or site policies;
9. SHOULD NOT listen for IPP Get-Notifications operation requests 10. SHOULD NOT listen for IPP Get-Notifications operation requests
on any other port, unless explicitly configured by system on any other port, unless explicitly configured by system
administrators or site policies. administrators or site policies.
13.2 Conformance for IPP Clients 13.2 Conformance for IPP Clients
IPP Clients that conform to this specification: IPP Clients that conform to this specification:
1. MUST create unambiguously unique 'ippget' URLs in all cases; 1.MUST create unambiguously unique 'ippget' URLs in all cases that
conform to the ABNF specified in section 11.5 of this document;
2. MUST send 'ippget' URLs (e.g., in the "notify-recipient-uri"
attribute in a Get-Notifications request) that conform to the
ABNF specified in section 11.5 of this document;
3. MUST send IPP Get-Notifications operation requests via the port 2.;MUST send IPP Get-Notifications operation requests via the port
specified in the associated 'ipp' URL (if present) or otherwise specified in the associated 'ipp' URL (if present) or otherwise
via IANA assigned well-known port 631; via IANA assigned well-known port 631;
4. MUST convert the associated 'ipp' URLs for use in IPP Get- 3.MUST convert the associated 'ipp' URLs for use in IPP Get-
Notifications operation to their corresponding 'http' URL forms Notifications operation to their corresponding 'http' URL forms
for use in the HTTP layer according to the rules in section 5 for use in the HTTP layer according to the rules in section 5
"IPP URL Scheme" in [RFC2910]. "IPP URL Scheme" in [RFC2910].
Note: The use of ambiguous 'ippget' URLs is NOT an optional feature Note: The use of ambiguous 'ippget' URLs is NOT an optional feature
for IPP Clients; it is a non-conformant implementation error. for IPP Clients; it is a non-conformant implementation error.
14 IANA Considerations 14 IANA Considerations
IANA shall register the 'ippget' URL scheme as defined in section 11 IANA shall register the 'ippget' URL scheme as defined in section 11
according to the procedures of [RFC2717]. according to the procedures of [RFC2717].
The rest of this section contains the exact information for IANA to The rest of this section contains the exact information for IANA to
add to the IPP Registries according to the procedures defined in RFC add to the IPP Registries according to the procedures defined in RFC
2911 [RFC2911] section 6. 2911 [RFC2911] section 6.
Note to RFC Editors: Replace RFC NNNN below with the RFC number Note to RFC Editors: Replace RFC NNNN below with the RFC number
for this document, so that it accurately reflects the content of for this document, so that it accurately reflects the content of
the information for the IANA Registry. the information for the IANA Registry.
14.1 Operation Registrations 14.1 Additional attribute value registrations for existing attributes
The following table lists the operation defined in this document.
This is to be registered according to the procedures in RFC 2911
[RFC2911] section 6.4.
Operations: Ref. Section:
Get-Notifications operation RFC NNNN 5
The resulting operation registration will be published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/operations/
area.
14.2 Additional attribute value registrations for existing attributes
This section lists additional attribute value registrations for use This section lists additional attribute value registrations for use
with existing attributes defined in other documents. with existing attributes defined in other documents.
14.2.1 Additional values for the "notify-schemes-supported" Printer 14.1.1 Additional values for the "notify-schemes-supported" Printer
attribute attribute
The following table lists the uriScheme value defined in this The following table lists the uriScheme value defined in this
document as an additional uriScheme value for use with the "notify- document as an additional uriScheme value for use with the "notify-
schemes-supported" Printer attribute defined in [ipp-ntfy]. This schemes-supported" Printer attribute defined in [ipp-ntfy]. This
is to be registered according to the procedures in RFC 2911 [RFC2911] is to be registered according to the procedures in RFC 2911 [RFC2911]
section 6.1. section 6.1.
uriScheme Attribute Values: Ref. Section: uriScheme Attribute Values: Ref. Section:
ippget RFC NNNN 9.1 ippget RFC NNNN 9.1
The resulting URI scheme attribute value registrations will be The resulting URI scheme attribute value registrations will be
published in the published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute- ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute-
values/notify-schemes-supported/ values/notify-schemes-supported/
area. area.
14.2.2 Additional values for the "operations-supported" Printer 14.1.2 Additional values for the "operations-supported" Printer
attribute attribute
The following table lists the enum attribute value defined in this The following table lists the enum attribute value defined in this
document as an additional type2 enum value for use with the document as an additional type2 enum value for use with the
"operations-supported" Printer attribute defined in [RFC2911]. This "operations-supported" Printer attribute defined in [RFC2911]. This
is to be registered according to the procedures in RFC 2911 [RFC2911] is to be registered according to the procedures in RFC 2911 [RFC2911]
section 6.1. section 6.1.
type2 enum Attribute Values: Value Ref. Section: type2 enum Attribute Values: Value Ref. Section:
Get-Notifications 0x001C RFC NNNN 9.2 Get-Notifications 0x001C RFC NNNN 9.2
The resulting enum attribute value registration will be published in The resulting enum attribute value registration will be published in
the the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute- ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute-
values/operations-supported/ values/operations-supported/
area. area.
14.2 Operation Registrations
The following table lists the operation defined in this document.
This is to be registered according to the procedures in RFC 2911
[RFC2911] section 6.4.
Operations: Ref. Section:
Get-Notifications operation RFC NNNN 5
The resulting operation registration will be published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/operations/
area.
14.3 Attribute Registrations 14.3 Attribute Registrations
The following table lists the attribute defined in this document. The following table lists the attribute defined in this document.
This is to be registered according to the procedures in RFC 2911 This is to be registered according to the procedures in RFC 2911
[RFC2911] section 6.2. [RFC2911] section 6.2.
Printer Description attributes: Ref. Section: Printer Description attributes: Ref. Section:
ippget-event-time-to-live (integer(0:MAX)) RFC NNNN 8.1 ippget-event-life (integer(15:MAX)) RFC NNNN 8.1
The resulting attribute registration will be published in the The resulting attribute registration will be published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attributes/ ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attributes/
area. area.
14.4 Status code Registrations 14.4 Status code Registrations
The following table lists the status code defined in this document. The following table lists the status code defined in this document.
This is to be registered according to the procedures in RFC 2911 This is to be registered according to the procedures in RFC 2911
[RFC2911] section 6.6. [RFC2911] section 6.6.
Status codes: Ref. Section: Status codes: Ref. Section:
redirection-other-site (0x0300) RFC NNNN 10.1 successful-ok-events-complete (0x0007) RFC NNNN 10.1
redirection-other-site (0x0300) RFC NNNN 10.2
The resulting status code registration will be published in the The resulting status code registration will be published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/status-codes/ ftp://ftp.iana.org/in-notes/iana/assignments/ipp/status-codes/
area. area.
15 Internationalization Considerations 15 Internationalization Considerations
The IPP Printer MUST localize the "notify-text" attribute as The IPP Printer MUST localize the "notify-text" attribute as
specified in section 14 of [ipp-ntfy]. specified in section 14 of [ipp-ntfy].
In addition, when the client receives the Get-Notifications response, In addition, when the client receives the Get-Notifications response,
skipping to change at page 30, line 31 skipping to change at page 36, line 9
security requirements (Client Authentication, Server Authentication security requirements (Client Authentication, Server Authentication
and Operation Privacy). Client Authentication is the mechanism by and Operation Privacy). Client Authentication is the mechanism by
which the client proves its identity to the server in a secure which the client proves its identity to the server in a secure
manner. Server Authentication is the mechanism by which the server manner. Server Authentication is the mechanism by which the server
proves its identity to the client in a secure manner. Operation proves its identity to the client in a secure manner. Operation
Privacy is defined as a mechanism for protecting operations from Privacy is defined as a mechanism for protecting operations from
eavesdropping. eavesdropping.
Unlike other Event Notification delivery methods in which the IPP Unlike other Event Notification delivery methods in which the IPP
Printer initiates the Event Notification, with the method defined in Printer initiates the Event Notification, with the method defined in
this document, the Notification Recipient is the client who s the this document, the Notification Recipient is the client who initiates
Get-Notifications operation. Therefore, there is no chance of "spam" the Get-Notifications operation. Therefore, there is no chance of
notifications with this method. Furthermore, such a client can close "spam" notifications with this method. Furthermore, such a client
down the HTTP channel at any time, and so can avoid future unwanted can close down the HTTP channel at any time, and so can avoid future
Event Notifications at any time. unwanted Event Notifications at any time.
Because the Get-Notifications operation is sent in the same direction
as Job Creation operations, this Event Notification Delivery Method
poses no additional firewall or port assignment issues.
17 References 17 References
[IANA-MT]
IANA Registry of Media Types: ftp://ftp.iana.orgisi.edu/in-
notes/iana/assignments/media-types/
[IANA-PORTREG]
IANA Port Numbers Registry. ftp://ftp.isi.edu/in-
notes/iana/assignments/port-numbers
[ipp-iig] [ipp-iig]
Hastings, T., Manros, C., Kugler, K, Holst H., Zehler, P., Hastings, T., Manros, C., Kugler, K, Holst H., Zehler, P.,
"Internet Printing Protocol/1.1: draft-ietf-ipp-implementers- "Internet Printing Protocol/1.1: draft-ietf-ipp-implementers-
guide-v11-03.txt, work in progress, July 17, 2001 guide-v11-03.txt, work in progress, July 17, 2001
[ipp-ntfy] [ipp-ntfy]
R. Herriot, Hastings, T., Isaacson, S., Martin, J., deBry, R., R. Herriot, Hastings, T., Isaacson, S., Martin, J., deBry, R.,
Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP
Event Notifications and Subscriptions", <draft-ietf-ipp-not-spec- Event Notifications and Subscriptions", <draft-ietf-ipp-not-spec-
07.txt>, July 17, 2001. 07.txt>, August 20, 2001.
[RFC1900] [RFC1900]
B. Carpenter, Y. Rekhter. Renumbering Needs Work, RFC 1900, B. Carpenter, Y. Rekhter. Renumbering Needs Work, RFC 1900,
February 1996. February 1996.
[RFC2026] [RFC2026]
S. Bradner, "The Internet Standards Process -- Revision 3", RFC S. Bradner, "The Internet Standards Process -- Revision 3", RFC
2026, October 1996. 2026, October 1996.
[RFC2119] [RFC2119]
skipping to change at page 32, line 14 skipping to change at page 37, line 43
[RFC2569] [RFC2569]
Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between
LPD and IPP Protocols", RFC 2569, April 1999. LPD and IPP Protocols", RFC 2569, April 1999.
[RFC2616] [RFC2616]
R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P.
Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1", Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1",
RFC 2616, June 1999. RFC 2616, June 1999.
[RFC2707]
Bergman, R., Hastings, T., Isaacson, S., and H. Lewis, "Job
Monitoring MIB - V1.0", November 1999.
[RFC2717] [RFC2717]
R. Petke and I. King, "Registration Procedures for URL Scheme R. Petke and I. King, "Registration Procedures for URL Scheme
Names", RFC 2717, November 1999. Names", RFC 2717, November 1999.
[RFC2732] [RFC2732]
R. Hinden, B. Carpenter, L. Masinter. Format for Literal IPv6 R. Hinden, B. Carpenter, L. Masinter. Format for Literal IPv6
Addresses in URL's, RFC 2732, December 1999. Addresses in URL's, RFC 2732, December 1999.
[RFC2910] [RFC2910]
Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
 End of changes. 

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