draft-ietf-ipp-notify-get-10.txt   rfc3996.txt 
Internet Printing Protocol WG R. Herriot Network Working Group R. Herriot
INTERNET-DRAFT Global Workflow Solutions Request for Comments: 3996 Global Workflow Solutions
<draft-ietf-ipp-notify-get-10.txt> T. Hastings Updates: 2911 T. Hastings
Updates: RFC 2911 and [ipp-ntfy] Xerox Corp. Category: Standards Track Xerox Corp.
[Target category: standards track] H. Lewis H. Lewis
Expires: December 21,2004 IBM Corp. IBM Corp.
June 21,2004 March 2005
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 (2003). All Rights Reserved. Status of This Memo
Status of this Memo: This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2005).
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026. Internet-Drafts are
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Abstract Abstract
This document describes an extension to the Internet Printing This document describes an extension to the Internet Printing
Protocol/1.1: Model and Semantics (RFC 2911, RFC 2910). This Protocol1.1: Model and Semantics (RFC 2911, RFC 2910). This document
document specifies the 'ippget' Pull Delivery Method for use with the specifies the 'ippget' Pull Delivery Method for use with the
"Internet Printing Protocol (IPP): Event Notifications and "Internet Printing Protocol (IPP): Event Notifications and
Subscriptions" specification (ipp-ntfy). This IPPGET Delivery Method Subscriptions" specification (RFC 3995). This IPPGET Delivery Method
is REQUIRED for all clients and Printers that support ipp-ntfy. The is REQUIRED for all clients and Printers that support RFC 3995. The
Notification Recipient, acting as a client, fetches (pulls) Event Notification Recipient, acting as a client, fetches (pulls) Event
Notifications using the Get-Notifications operation defined in this Notifications by using the Get-Notifications operation defined in
document. this document.
Table of Contents Table of Contents
1 Introduction.....................................................4 1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Terminology......................................................4 2.1. Conformance Terminology . . . . . . . . . . . . . . . . 4
2.1 Conformance Terminology........................................4 2.2. Other Terminology . . . . . . . . . . . . . . . . . . . 4
2.2 Other terminology..............................................5 3. Model and Operation . . . . . . . . . . . . . . . . . . . . . 4
4. General Information . . . . . . . . . . . . . . . . . . . . . 5
3 Model and Operation..............................................5 5. Get-Notifications Operation . . . . . . . . . . . . . . . . . 7
5.1. Get-Notifications Request . . . . . . . . . . . . . . . 8
4 General Information..............................................7 5.1.1. notify-subscription-ids (1setOf integer(1:MAX)) 8
5.1.2. notify-sequence-numbers (1setOf integer(1:MAX)) 9
5 Get-Notifications operation......................................8 5.1.3. notify-wait (boolean) . . . . . . . . . . . . . 10
5.1 Get-Notifications Request......................................9 5.2. Get-Notifications Response. . . . . . . . . . . . . . . 10
5.1.1 notify-subscription-ids (1setOf integer(1:MAX)).............10 5.2.1. notify-get-interval (integer(0:MAX)). . . . . . 13
5.1.2 notify-sequence-numbers (1setOf integer(1:MAX)).............10 5.2.2. printer-up-time (integer(1:MAX)). . . . . . . . 14
5.1.3 notify-wait (boolean).......................................11 6. Additional Information about Subscription Template Attributes 17
5.2 Get-Notifications Response....................................11 6.1. notify-pull-method (type2 keyword). . . . . . . . . . . 17
5.2.1 notify-get-interval (integer(0:MAX))........................14 7. Subscription Description Attributes . . . . . . . . . . . . . 18
5.2.2 printer-up-time (integer(1:MAX))............................16 8. Additional Printer Description Attributes . . . . . . . . . . 18
8.1. ippget-event-life (integer(15:MAX)) . . . . . . . . . . 18
6 Additional Information about Subscription Template Attributes...19 9. New Values for Existing Printer Description Attributes. . . . 19
6.1 notify-pull-method (type2 keyword)............................19 9.1. notify-pull-method-supported (1setOf type2 keyword) . . 19
9.2. operations-supported (1setOf type2 enum). . . . . . . . 19
7 Subscription Description Attributes.............................19 10. New Status Codes. . . . . . . . . . . . . . . . . . . . . . . 19
10.1. successful-ok-events-complete (0x0007) . . . . . . . . 20
8 Additional Printer Description Attributes.......................19 11. Encoding and Transport. . . . . . . . . . . . . . . . . . . . 20
8.1 ippget-event-life (integer(15:MAX))...........................19 12. Conformance Requirements. . . . . . . . . . . . . . . . . . . 21
12.1. Conformance for IPP Printers . . . . . . . . . . . . . 21
9 New Values for Existing Printer Description Attributes..........21 12.2. Conformance for IPP Clients. . . . . . . . . . . . . . 22
9.1 notify-pull-method-supported (1setOf type2 keyword)...........21 13. Normative References. . . . . . . . . . . . . . . . . . . . . 23
9.2 operations-supported (1setOf type2 enum)......................21 14. Informative References. . . . . . . . . . . . . . . . . . . . 23
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
10 New Status Codes...............................................21 15.1. Attribute Registrations. . . . . . . . . . . . . . . . 24
10.1 successful-ok-events-complete (0x0007).......................21 15.2. Delivery Method and Additional Keyword Attribute Value
registrations for Existing Attributes. . . . . . . . . 24
11 Encoding and Transport.........................................22 15.3. Additional Enum Attribute Values . . . . . . . . . . . 25
15.4. Operation Registrations. . . . . . . . . . . . . . . . 25
12 Conformance Requirements.......................................23 15.5. Status Code Registrations. . . . . . . . . . . . . . . 25
12.1 Conformance for IPP Printers.................................23 16. Internationalization Considerations . . . . . . . . . . . . . 25
12.2 Conformance for IPP Clients..................................24 17. Security Considerations . . . . . . . . . . . . . . . . . . . 26
17.1. Notification Recipient Client Access Rights. . . . . . 26
13 Normative References...........................................25 17.2. Printer Security Threats . . . . . . . . . . . . . . . 27
17.3. Notification Recipient Security Threats. . . . . . . . 27
14 Informative References.........................................25 17.4. Security Requirements for Printers . . . . . . . . . . 27
17.5. Security Requirements for clients. . . . . . . . . . . 28
15 IANA Considerations............................................26 18. Description of Base IPP Documents (Informative) . . . . . . . 28
15.1 Attribute Registrations......................................26 19. Contributors. . . . . . . . . . . . . . . . . . . . . . . . . 29
15.2 Delivery Method and Additional keyword attribute value Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30
registrations for existing attributes.............................26 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 31
15.3 Additional enum attribute values.............................27
15.4 Operation Registrations......................................27
15.5 Status code Registrations....................................27
16 Intellectual Property..........................................28
17 Internationalization Considerations............................28
18 Security Considerations........................................28
18.1 Notification Recipient client access rights..................29
18.2 Printer security threats.....................................29
18.3 Notification Recipient security threats......................29
18.4 Security requirements for Printers...........................30
18.5 Security requirements for clients............................30
19 Contributors...................................................30
20 Authors' Addresses.............................................31
21 Description of Base IPP documents (Informative)................31
22 Full Copyright Statement.......................................32
Table of Tables Table of Tables
Table 1 - Information about the Delivery Method....................7 Table 1. Information about the Delivery Method. . . . . . . . . . 5
Table 2 - Combinations of "notify-wait", "status-code", and "notify- Table 2. Combinations of "notify-wait", "status-code", and
get-interval".................................................15 "notify-get-interval". . . . . . . . . . . . . . . . . . 13
Table 3 - Attributes in Event Notification Content................17 Table 3. Attributes in Event Notification Content . . . . . . . . 15
Table 4 - Additional Attributes in Event Notification Content for Job Table 4. Additional Attributes in Event Notification Content for
Events........................................................18 Job Events . . . . . . . . . . . . . . . . . . . . . . . 16
Table 5 - Combinations of Events and Subscribed Events for "job-
impressions-completed"........................................18
Table 6 - Additional Attributes in Event Notification Content for
Printer Events................................................19
Table 7 - Operation-id assignments................................21
Table 8 - The "event-notification-attributes-tag" value...........23
1 Introduction Table 5. Combinations of Events and Subscribed Events for "job-
impressions-completed" . . . . . . . . . . . . . . . . . 17
Table 6. Additional Attributes in Event Notification Content for
Printer Events . . . . . . . . . . . . . . . . . . . . . 17
Table 7. Operation-id Assignments . . . . . . . . . . . . . . . . 19
Table 8. The "event-notification-attributes-tag" Value. . . . . . 21
1. Introduction
This document describes an extension to the Internet Printing This document describes an extension to the Internet Printing
Protocol/1.1: Model and Semantics [RFC 2911], [RFC 2910]. This Protocol/1.1: Model and Semantics [RFC 2911], [RFC 2910]. This
document specifies the 'ippget' Pull Delivery Method for use with the document specifies the 'ippget' Pull Delivery Method for use with the
"Internet Printing Protocol (IPP): Event Notifications and "Internet Printing Protocol (IPP): Event Notifications and
Subscriptions" specification [ipp-ntfy]. This IPPGET Delivery Method Subscriptions" specification [RFC3995]. This IPPGET Delivery Method
is REQUIRED for all clients and Printers that support [ipp-ntfy]. is REQUIRED for all clients and Printers that support [RFC3995]. The
The Notification Recipient, acting as a client, fetches (pulls) Event Notification Recipient, acting as a client, fetches (pulls) Event
Notifications using the Get-Notifications operation defined in this Notifications by using the Get-Notifications operation defined in
document. For a description of the base IPP documents, see section this document. For a description of the base IPP documents, see
21 of this document. For a description of the IPP Event Notification section 21 of this document. For a description of the IPP Event
Model, see [ipp-ntfy]. Notification Model, see [RFC3995].
With this Pull Delivery Method, when an Event occurs, the Printer With this Pull Delivery Method, when an Event occurs, the Printer
saves the Event Notification for a period of time called the Event saves the Event Notification for a period of time called the Event
Life. The Notification Recipient fetches (pulls) the Event Life. The Notification Recipient fetches (pulls) the Event
Notifications using the Get-Notifications operation. This operation Notifications by using the Get-Notifications operation. This
causes the Printer to return all Event Notifications held for the operation causes the Printer to return all Event Notifications held
specified Subscription object(s). If the Notification Recipient has for the specified Subscription object(s). If the Notification
selected the Event Wait Mode option to wait for additional Event Recipient has selected the Event Wait Mode option to wait for
Notifications, the Printer MAY continue to return Event Notifications additional Event Notifications, the Printer MAY continue to return
to the Notification Recipient as asynchronous Get-Notification Event Notifications to the Notification Recipient as asynchronous
responses as Events occur using the transaction originated by the Get-Notification responses as Events occur using the transaction
Notification Recipient. originated by the Notification Recipient.
The Notification Recipient can terminate Event Wait Mode (without The Notification Recipient can terminate Event Wait Mode (without
closing the connection) by supplying the "notify-wait" (boolean) closing the connection) by supplying the "notify-wait" (boolean)
attribute with a 'false' value in a subsequent Get-Notifications attribute with a 'false' value in a subsequent Get-Notifications
request. Similarly, the Printer can terminate Event Wait Mode request. Similarly, the Printer can terminate Event Wait Mode
(without closing the connection) by returning the "notify-get- (without closing the connection) by returning the "notify-get-
interval" (integer) operation attribute in a Get-Notifications interval" (integer) operation attribute in a Get-Notifications
response which tells the Notification Recipient how long to wait response that tells the Notification Recipient how long to wait
before trying again. 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:
2.1 Conformance Terminology 2.1. Conformance Terminology
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 [RFC2119] and [RFC2911], section 12.1. If
12.1. If an implementation supports the extension defined in this an implementation supports the extension defined in this document,
document, then these terms apply; otherwise, they do not. These then these terms apply; otherwise, they do not. These terms define
terms define conformance to this document only; they do not affect conformance to this document only; they do not affect conformance to
conformance to other documents, unless explicitly stated otherwise. other documents, unless it is explicitly stated otherwise.
2.2 Other terminology 2.2. Other terminology
This document uses the same terminology as [RFC2911], such as This document uses the same terminology as [RFC2911], including
"client", "Printer", "Job", "attribute", "attribute value", "client", "Printer", "Job", "attribute", "attribute value",
"keyword", "operation", "request", "response", and "support" with the "keyword", "operation", "request", "response", and "support", with
same meanings. This document also uses terminology defined in [ipp- the same meanings. This document also uses terminology defined in
ntfy], such as "Subscription (object)", "Notification Recipient", [RFC3995], such as "Subscription (object)", "Notification Recipient",
"Event", "Event Notification", "Compound Event Notification", "Event "Event", "Event Notification", "Compound Event Notification", "Event
Life", and "Event Notification Attribute Group" with the same Life", and "Event Notification Attribute Group", with the same
meanings. In addition, this document defines the following terms for meanings. In addition, this document defines the following terms for
use in this document: use in this document:
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 client in its Get-Notifications Request and granted by a Printer
to keep the connection open while the Printer sends subsequent to keep the connection open while the Printer sends subsequent
Event Notifications to the Notification Recipient as they occur Get-Notification operation responses to the Notification
as additional Get-Notification operation responses. Recipient in the form of Event Notifications as they occur.
3 Model and Operation 3. Model and Operation
In a Subscription Creation Operation, when the "notify-pull-method" In a Subscription Creation Operation, when the "notify-pull-method"
attribute is present and has the 'ippget' keyword value, the client attribute is present and has the "ippget" keyword value, the client
is requesting that the Printer use the 'ippget' Pull Delivery Method is requesting that the Printer use the "ippget" Pull Delivery Method
for the Event Notifications associated with the new Subscription for the Event Notifications associated with the new Subscription
Object. Object.
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 Life. The Printer MUST hold an Event and MUST assign it the Event Life. The Printer MUST hold an Event
Notification for its assigned Event Life. Notification for its assigned Event Life.
When a Notification Recipient wants to receive Event Notifications When a Notification Recipient wants to receive Event Notifications
for a Subscription object, it performs the Get-Notifications for a Subscription object, it performs the Get-Notifications
operation supplying the Subscription object's subscription-id, which operation supplying the Subscription object's subscription-id, which
causes the Printer to return all un-expired Event Notifications held causes the Printer to return all un-expired Event Notifications held
for that Subscription object. If the Notification Recipient has for that Subscription object. If the Notification Recipient has
selected the Event Wait Mode option to wait for additional Event 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 that Subscription Notifications in the response as Events occur for that Subscription
object. object.
When the Notification Recipient requests Event Notifications for per- When the Notification Recipient requests Event Notifications for
Job Subscription Objects, the Notification Recipient typically Per-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
MUST save Event Notifications for at least 15 seconds (see section MUST save Event Notifications for at least 15 seconds (see section
8.1), the Notification Recipient is unlikely to miss any Event 8.1), the Notification Recipient is unlikely to miss any Event
Notifications that occur between the Subscription Creation and the Notifications that occur between the Subscription Creation and the
Get-Notifications operation. Get-Notifications operation.
The 'ippget' Delivery Method is designed primarily for (1) a client The 'ippget' Delivery Method is designed primarily for (1) a client
that wants to get Events (from the job's per-Job Subscription object) 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 for a job that it has submitted and (2) a privileged client that
wants to get all job or printer Events from a per-Printer wants to get all job or printer Events from a Per-Printer
Subscription object. Subscription object.
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' keyword method 1. What is the URL scheme name for the 'ippget' keyword method
Push Delivery Method or the keyword name Push Delivery Method, or the keyword name
method name for the Pull Delivery method name for the Pull Delivery
Method? Method?
2. Is the Delivery Method REQUIRED, REQUIRED
RECOMMENDED or OPTIONAL for an IPP 2. Is the Delivery Method REQUIRED, REQUIRED
Printer to support? RECOMMENDED, or OPTIONAL for an IPP
3. What transport and delivery protocols IPP with one new Printer to support?
does the Printer use to deliver the operation.
Event Notification Content, i.e., what 3. What transport and delivery protocols IPP with one new
is the entire network stack? does the Printer use to deliver the operation.
4. Can several Event Notifications be Yes. Event Notification Content; i.e.,
combined into a Compound Event what is the entire network stack?
Notification?
5. Is the Delivery Method initiated by This Delivery Method is 4. Can several Event Notifications be Yes.
the Notification Recipient (pull), or a pull method with combined into a Compound Event
by the Printer (push)? aspects of a push Notification?
5. Is the Delivery Method initiated by This Delivery Method is
the Notification Recipient (pull), a pull method with
or by the Printer (push)? aspects of a push
method, though the method, though the
Printer does not Printer does not
initiate the operation. initiate the operation.
6. Is the Event Notification content Machine Consumable
Machine Consumable or Human
Consumable?
7. What section in this document answers Section 5
the following question? For a Machine
Consumable Event Notification, what is
the representation and encoding of
values defined in section 9.1 of [ipp-
ntfy] and the conformance requirements
thereof? For a Human Consumable Event
Notification, what is the
representation and encoding of pieces
of information defined in section 9.2
of [ipp-ntfy] and the conformance
requirements thereof?
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 6. Is the Event Notification content Machine Consumable.
transport and delivery protocol, e.g., underlying HTTP Machine Consumable or Human
how it is handled in firewalls? transport and in the Consumable?
same direction, so no
7. What section in this document answers Section 5.
the following questions? For a Machine
Consumable Event Notification, what is
the representation and encoding of
values defined in section 9.1 of
[RFC3995], and what are the
conformance requirements thereof? For
a Human Consumable Event Notification,
what is the representation and
encoding of pieces of information
defined in section 9.2 of
[RFC3995], and the conformance
requirements thereof?
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
transport and delivery protocol; underlying HTTP
e.g., how it is handled in transport and in the
firewalls? same direction, so no
new firewall new firewall
considerations. considerations.
10.What are the content length None
restrictions?
11.What are the additional values or None
pieces of information that a Printer
sends in an Event Notification content
and the conformance requirements
thereof?
12.What are the additional Subscription None
Template and/or Subscription
Description attributes and the
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 10. What are the content length None.
restrictions?
11. What are the additional values or None.
pieces of information that a Printer
sends in an Event Notification content
and the conformance requirements
thereof?
12. What are the additional Subscription None.
Template and/or Subscription
Description attributes and the
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
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 requesting the Printer to return all Event Notification Recipient requesting the Printer to return all Event
Notifications held for the identified Subscription object(s). Notifications held for the identified Subscription object(s).
A Printer MUST support this operation, MUST accept the request in any A Printer MUST support this operation, MUST accept the request in any
state (see [RFC2911] "printer-state" and "printer-state-reasons" state (see [RFC2911] "printer-state" and "printer-state-reasons"
attributes), and MUST remain in the same state with the same attributes), and MUST remain in the same state with the same
"printer-state-reasons" values. "printer-state-reasons" values.
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"
Subscription Description attribute equals one of the values of Subscription Description attribute equals one of the values of
the "notify-subscription-ids" (1setOf integer(1:MAX)) operation the "notify-subscription-ids" (1setOf integer(1:MAX)) operation
attribute AND attribute AND
2. Whose associated Subscription Object's contains the "notify- 2. whose associated Subscription Object contains the "notify-pull-
pull-method" attribute and it has the 'ippget' keyword value AND method" attribute and it has the 'ippget' keyword value, AND
3. Whose "notify-sequence-number" is equal to or greater than the 3. whose "notify-sequence-number" is equal to or greater than the
corresponding value of the "notify-sequence-numbers (1setOf corresponding value of the "notify-sequence-numbers" (1setOf
integer(1:MAX)) operation attribute, if supplied AND integer(1:MAX)) operation attribute if supplied AND
4. Whose Event Life has not yet expired AND 4. whose Event Life has not yet expired AND
5. Where the Notification Recipient client has read-access rights 5. where the Notification Recipient client has read-access rights to
to the identified Subscription Object (see Access Rights the identified Subscription Object (see Access Rights paragraph
paragraph below). below).
The Notification Recipient client MUST either: (a) request Event Wait The Notification Recipient client MUST either (a) request Event Wait
Mode by supplying the "notify-wait" operation attribute with a 'true' Mode by supplying the "notify-wait" operation attribute with a 'true'
value or (b) suppress Event Wait Mode by omitting the "notify-wait" value or (b) suppress Event Wait Mode by omitting the "notify-wait"
operation attribute or by supplying it with a 'false' value. In operation attribute or by supplying it with a 'false' value. To
order to terminate Event Wait Mode subsequently, the Notification terminate Event Wait Mode subsequently, the Notification Recipient
Recipient client MUST close the connection. In order to terminate client MUST close the connection. To terminate Event Wait Mode, the
Event Wait Mode, the Printer MUST either (a) return the "notify-get- Printer MUST either (a) return the "notify-get-interval" operation
interval" operation attribute in a Get-Notifications response attribute in a Get-Notifications response (RECOMMENDED behavior) or
(RECOMMENDED behavior) or (b) close the connection. The "notify-get- (b) close the connection. The "notify-get-interval" operation
interval" operation attributes tells the Notification Recipient how attributes tell the Notification Recipient how long to wait before
long to wait before trying a subsequent Get-Notifications request. trying a subsequent Get-Notifications request.
Access Rights: The authenticated user (see [RFC2911] section 8.3) Access Rights: The authenticated user (see [RFC2911], section 8.3)
performing this operation MUST be (1) the owner of each Subscription performing this operation MUST be (1) the owner of each Subscription
Object identified by the "notify-subscription-ids" operation Object identified by the "notify-subscription-ids" operation
attribute (see section 5.1.1), (2) an operator or administrator of attribute (see section 5.1.1), (2) an operator or administrator of
the Printer (see [RFC2911] Sections 1 and 8.5), or (3) be otherwise the Printer (see [RFC2911], sections 1 and 8.5), or (3) otherwise
authorized by the Printer's administrator-configured security policy authorized by the Printer's administrator-configured security policy
to request Event Notifications from the target Subscription to request Event Notifications from the target Subscription
Object(s). Otherwise, the IPP Printer MUST reject the operation and Object(s). Otherwise, the IPP Printer MUST reject the operation and
return: 'client-error-forbidden', 'client-error-not-authenticated', return: 'client-error-forbidden', 'client-error-not-authenticated',
or 'client-error-not-authorized' status code as appropriate. or 'client-error-not-authorized' status code, as appropriate.
Furthermore, the Printer's security policy MAY limit the attributes Furthermore, the Printer's security policy MAY limit the attributes
returned by the Get-Notifications operation, in a manner similar to returned by the Get-Notifications operation, in a manner similar to
the Get-Job-Attributes operation (see [RFC2911] end of section that of the Get-Job-Attributes operation (see [RFC2911], end of
3.3.4.2). section 3.3.4.2).
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 that 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.
5.1.1 notify-subscription-ids (1setOf integer(1:MAX)) 5.1.1. notify-subscription-ids (1setOf integer(1:MAX))
This attribute identifies one or more Subscription objects for This attribute identifies one or more Subscription objects for which
which Events are requested. The client MUST supply this Events are requested. The client MUST supply this attribute with at
attribute with at least one value. The Printer object MUST least one value. The Printer object MUST support this attribute with
support this attribute with multiple values. multiple values.
If no Subscription Object exists with the supplied identifier If no Subscription Object exists with the supplied identifier, or if
or the identified Subscription Object does not contain the the identified Subscription Object does not contain the "notify-
"notify-pull-method" attribute with the 'ippget' keyword value, pull-method" attribute with the 'ippget' keyword value, the Printer
the Printer MUST return the 'client-error-not-found' status MUST return the 'client-error-not-found' status code.
code.
Note: The name of both the "notify-subscription-ids" and Note: The name of both the "notify-subscription-ids" and
"notify-sequence-numbers" end in 's', since they are "notify-sequence-numbers" end in 's', as they are multi-valued.
multi-valued. However, there are other occurrences of However, there are other occurrences of these attribute names
these attribute names without the 's' that are single without the 's' that are single valued.
valued.
5.1.2 notify-sequence-numbers (1setOf integer(1:MAX)) 5.1.2. notify-sequence-numbers (1setOf integer(1:MAX))
This attribute specifies one or more lowest Event Notification This attribute specifies one or more of the lowest Event Notification
sequence number values for the Subscription objects identified sequence number values for the Subscription objects identified by the
by the corresponding values of the "notify-subscription-ids" corresponding values of the "notify-subscription-ids" operation
operation attribute. The Notification Recipient SHOULD supply attribute. The Notification Recipient SHOULD supply this attribute,
this attribute and the number of values SHOULD be the same as and the number of values SHOULD be the same as that of the "notify-
the number of values of the "notify-subscriptions-ids" subscriptions-ids" attribute. The Printer MUST support this
attribute. The Printer MUST support this attribute with attribute with multiple values.
multiple values.
The Printer MUST NOT return Notification Events with lower The Printer MUST NOT return Notification Events with lower sequence
sequence numbers for the corresponding Subscription object. numbers for the corresponding Subscription object. Therefore, by
Therefore, by supplying the proper values for this attribute supplying the proper values for this attribute the Notification
the Notification Recipient can prevent getting the same Event Recipient can prevent getting the same Event Notifications from a
Notifications from a Subscription object that were returned on Subscription object that were returned on a previous Get-
a previous Get-Notifications request. The Notification Notifications request. The Notification Recipient SHOULD remember
Recipient SHOULD remember the highest "notify-sequence-number" the highest "notify-sequence-number" value returned for each
value returned for each Subscription object requested and Subscription object requested and SHOULD pass that value for each
SHOULD pass that value for each requested Subscription object requested Subscription object on the next Get-Notifications request.
on the next Get-Notifications request.
If the Notification Recipient supplies fewer values for this If the Notification Recipient supplies fewer values for this
attribute (including omitting this attribute) than for the attribute (including omitting this attribute) than it does for the
"notify-subscription-ids" operation attribute, the Printer "notify-subscription-ids" operation attribute, the Printer assumes a
assumes a '1' value for each missing value. A value of '1' '1' value for each missing value. A value of '1' causes the Printer
causes the Printer to return any un-expired Event Notification to return any un-expired Event Notification for that Subscription
for that Subscription object, since '1' is the lowest possible object, as '1' is the lowest possible sequence number. If the
sequence number. If the Notification Recipient supplies more Notification Recipient supplies more values for this attribute than
values for this attribute than the number of values for the the number of values for the "notify-subscription-ids" operation
"notify-subscription-ids" operation attribute, the Printer attribute, the Printer ignores the extra values.
ignores the extra values.
Note: If a Notification Recipient performs two consecutive Get- Note: If a Notification Recipient performs two consecutive Get-
Notifications operations with the same value for "notify- Notifications operations with the same value for "notify-sequence-
sequence-number" (or omits the attribute), the time stamp of number" (or omits the attribute), the time stamp value of the first
the first Event Notification in the second Get-Notifications Event Notification in the second Get-Notifications Response may be
Response may be less than the time stamp of the last Event less than that of the time stamp of the last Event Notification in
Notification in the first Get-Notification Response. This the first Get-Notification Response. This happens because the
happens because the Printer sends all unexpired Event Printer sends all unexpired Event Notifications with an equal or
Notification with a sequence number equal or higher according higher sequence number according to the ordering specified in
to the ordering specified in [ipp-ntfy] and some Event [RFC3995], and some Event Notifications from the first Get-
Notifications from the first Get-Notifications operation may Notifications operation may not have expired by the time the second
not have expired by the time the second Get-Notifications Get-Notifications operation occurs.
operation occurs.
5.1.3 notify-wait (boolean) 5.1.3. notify-wait (boolean)
This value indicates whether or not the Notification Recipient This value indicates whether the Notification Recipient wants Event
wants Event Wait Mode. The client MAY supply this attribute. Wait Mode. The client MAY supply this attribute. The Printer object
The Printer object MUST support both values of this attribute. MUST support both values of this attribute.
If the client supplies the 'false' value or omits this If the client supplies the 'false' value or omits this attribute, the
attribute, the client is not requesting Event Wait Mode. If client is not requesting Event Wait Mode. If the value is 'true',
the value is 'true', the client is requesting Event Wait Mode. the client is requesting Event Wait Mode. See the beginning of
See the beginning of section 5.2 for the rules for Event Wait section 5.2 for the rules for Event Wait Mode.
Mode.
5.2 Get-Notifications Response 5.2. Get-Notifications Response
The Printer has the following options for responding to a Get- The Printer has the following options for responding to a Get-
Notifications Request: Notifications Request:
1. The Printer can reject the request and return the 'server-error- 1. The Printer can reject the request and return the 'server-error-
busy' status code, if the Printer is too busy to accept this busy' status code if the Printer is too busy to accept this
operation at this time. In this case, the Printer MUST return operation at this time. In this case, the Printer MUST return
the "get-notify-interval" operation attribute to indicate when the "get-notify-interval" operation attribute to indicate when
the client SHOULD try again. the client SHOULD try again.
2. If the Notification Recipient did not request Event Wait Mode 2. If the Notification Recipient did not request Event Wait Mode
("notify-wait-mode" = 'false' or omitted), the Printer MUST ("notify-wait-mode" = 'false' or omitted), the Printer MUST
return immediately whatever Event Notifications it currently immediately return whatever Event Notifications it currently
holds in the requested Subscription object(s) and MUST return holds in the requested Subscription object(s) and MUST return the
the "notify-get-interval" operation attribute with number of "notify-get-interval" operation attribute with the number of
seconds from now at which the Notification Recipient SHOULD seconds from now, at which the Notification Recipient SHOULD
repeat the Get-Notifications Request to get future Event repeat the Get-Notifications Request to get future Event
Notifications. Notifications.
3. If the Notification Recipient requested Event Wait Mode 3. If the Notification Recipient requested Event Wait Mode
("notify-wait-mode" = 'true'), the Printer MUST return ("notify-wait-mode" = 'true'), the Printer MUST immediately
immediately whatever Event Notifications it currently holds in return whatever Event Notifications it currently holds in the
the requested Subscription object(s) and MUST continue to return requested Subscription object(s) and MUST continue to return
Event Notifications as they occur until all of the requested Event Notifications as they occur until all the requested
Subscription Objects are canceled. A Subscription Object is Subscription Objects are canceled. A Subscription Object is
canceled either via the Cancel-Subscription operation or by the canceled either via the Cancel-Subscription operation or by the
Printer (e.g., the Subscription Object is canceled when the Printer (e.g., the Subscription Object is canceled when the
associated Job completes and is no longer in the Job Retention associated Job completes and is no longer in the Job Retention or
or Job History phase - see the "ippget-event-life Job History phase; see the "ippget-event-life (integer(15:MAX))"
(integer(15:MAX))" attribute discussion in section 8.1). attribute discussion in section 8.1).
However, the Printer MAY decide to terminate Event Wait Mode at However, the Printer MAY decide to terminate Event Wait Mode at
any time, including in the first response. In this case the any time, including in the first response. In this case, the
Printer MUST return the "notify-get-interval" operation Printer MUST return the "notify-get-interval" operation
attribute. This attribute indicates that the Printer wishes to attribute. This attribute indicates that the Printer wishes to
leave Event Wait Mode and the number of seconds in the future leave Event Wait Mode and the number of seconds in the future
that the Notification Recipient SHOULD try the Get-Notifications that the Notification Recipient SHOULD try the Get-Notifications
operation again. The Notification Recipient MUST accept this operation again. The Notification Recipient MUST accept this
response and MUST disconnect. If the Notification Recipient response and MUST disconnect. If the Notification Recipient does
does not disconnect, the Printer SHOULD do so. not disconnect, the Printer SHOULD do so.
From the Notification Recipient's view, the response appears as an From the Notification Recipient's view, the response appears as an
initial burst of data, which includes the Operation Attributes Group initial burst of data, which includes the Operation Attributes Group
and one Event Notification Attributes Group per Event Notification and one Event Notification Attributes Group per Event Notification
that the Printer is holding. After the initial burst of data, if the that the Printer is holding. After the initial burst of data, if the
Notification Recipient has selected the Event Wait Mode option to Notification Recipient has selected the Event Wait Mode option to
wait for additional Event Notifications, the Notification Recipient wait for additional Event Notifications, the Notification Recipient
receives occasional Event Notification Attribute Groups. Proxy receives occasional Event Notification Attribute Groups. Proxy
servers may delay some Event Notifications or cause time-outs to servers may delay some Event Notifications or cause time-outs to
occur. The client MUST be prepared to perform the Get-Notifications occur. The client MUST be prepared to perform the Get-Notifications
operation again when time-outs occur. operation again when time-outs occur.
Each attribute is encoded using the IPP rules for encoding attributes Each attribute is encoded by using the IPP rules for encoding
[RFC2910] and MAY be encoded in any order. Note: the Get-Jobs attributes [RFC2910] and MAY be encoded in any order. Note: the
response in [RFC2911] acts as a model for encoding multiple groups of Get-Jobs response in [RFC2911] acts as a model for encoding multiple
attributes. See section 11 for the encoding and transport rules. groups of attributes. See section 11 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:
In addition to the REQUIRED status code returned in every Status Message: In addition to the REQUIRED status code returned
response, the response OPTIONALLY includes a "status-message" in every response, the response OPTIONALLY includes a "status-
(text(255)) and/or a "detailed-status-message" (text(MAX)) message" (text(255)) and/or a "detailed-status-message"
operation attribute as described in [RFC2911] sections 13 and (text(MAX)) operation attribute, as described in [RFC2911],
3.1.6. sections 13 and 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 are descriptions 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 subscription-ids that had associated with the specified subscription-ids that had
been supplied in the "notify-subscription-ids" operation been supplied in the "notify-subscription-ids" operation
attribute in the request. If the requested Subscription attribute in the request. If the requested Subscription
Objects have no associated Event Notification, the Objects have no associated Event Notification, the
response MUST contain zero Event Notifications. response MUST contain zero Event Notifications.
successful-ok-events-complete: indicate when this return
successful-ok-events-complete: Indicates when this return
is the last return for all Subscription objects that is the last return for all Subscription objects that
match the request, whether or not there are Event match the request, whether or not Event Notifications are
Notifications being returned. This condition occurs for returned. This condition occurs for Event Wait Mode with
Event Wait Mode with Notification Recipients waiting for Notification Recipients waiting for responses when (1)
responses when the Subscription Object is: (1) canceled the Subscription Object is canceled with a Cancel-
with a Cancel-Subscription operation, (2) deleted when Subscription operation, (2) the Subscription Object is
the Per-Printer Subscription lease time expires, or (3) deleted, when the Per-Printer Subscription lease time
when the 'job-completed' event occurs for a Per-Job expires, or (3) the 'job-completed' event occurs for a
Subscription. This condition also occurs for a Get- Per-Job Subscription. This condition also occurs for a
Notifications request that a Notification Recipient makes Get-Notifications request that a Notification Recipient
after the job completes, but before the Event Life makes after the job completes, but before the Event Life
expires. See section 10.1. 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-subscription-id" attribute equals Objects whose "notify-subscription-id" attribute equals
any of the values of the "notify-subscription-ids" any of the values of the "notify-subscription-ids"
operation attribute supplied or the identified operation attribute supplied, or the identified
Subscription Object does not contain the "notify-pull- Subscription Object does not contain the "notify-pull-
method" attribute with the 'ippget' keyword value. method" attribute with the 'ippget' keyword value.
server-error-busy: The Printer is too busy to accept this server-error-busy: The Printer is too busy to accept this
operation. The Printer SHOULD return the "notify-get- operation. The Printer SHOULD return the "notify-get-
interval" operation attribute in the Operation Attributes interval" operation attribute in the Operation Attributes
of the response, then the Notification Recipient SHOULD of the response; then the Notification Recipient SHOULD
wait for the number of seconds specified by the "notify- wait for the number of seconds specified by the "notify-
get-interval" operation attribute before performing this get-interval" operation attribute before performing this
operation again. If the "notify-get-interval" Operation operation again. If the "notify-get-interval" Operation
Attribute is not present, the Notification Recipient Attribute is not present, the Notification Recipient
SHOULD use the normal network back-off algorithms for SHOULD use the normal network back-off algorithms to
determining when to perform this operation again. determine when to perform this operation again.
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, attributes is the same in all Subscription Objects. If not,
the Printer MUST pick one Subscription Object from which to the Printer MUST pick one Subscription Object from which to
obtain the value of these attributes. The algorithm for obtain the value of these attributes. The algorithm for
picking the Subscription Object is implementation dependent. picking the Subscription Object is implementation dependent.
The choice of natural language is not critical because 'text' The choice of natural language is not critical, because 'text'
and 'name' values can override the "attributes-natural- and 'name' values can override the "attributes-natural-
language" operation attribute. The Printer's choice of charset language" operation attribute. The Printer's choice of charset
is critical because a bad choice may leave it unable to send is critical because a bad choice may leave it unable to send
some 'text' and 'name' values accurately. some 'text' and 'name' values accurately.
5.2.1 notify-get-interval (integer(0:MAX)) 5.2.1. notify-get-interval (integer(0:MAX))
The value of this operation attribute is the number of seconds The value of this operation attribute is the number of seconds that
that the Notification Recipient SHOULD wait before trying the the Notification Recipient SHOULD wait before trying the Get-
Get-Notifications operation again. The Printer MUST return Notifications operation again. The Printer MUST return this
this operation attribute if: (1) it is too busy to return operation attribute if (1) it is too busy to return events, (2) the
events, (2) the Notification Recipient client did not request Notification Recipient client did not request Event Wait Mode, or (3)
Event Wait Mode, or (3) the Printer is terminating Event Wait the Printer is terminating Event Wait Mode. The client MUST accept
Mode. The client MUST accept this attribute and SHOULD re- this attribute and SHOULD reissue the Get-Notifications operation
issue the Get-Notifications operation (with or without "notify- (with or without "notify-wait" = 'true') at the indicated number of
wait" = 'true') the indicated number of seconds in the future seconds in the future in order to get more Event Notifications This
in order to get more Event Notifications This value is value is intended to help the client be a good network citizen.
intended to help the client be a good network citizen.
The value of this attribute MUST be at least as large as the The value of this attribute MUST be at least as large as that of the
value of the Printer's "ippget-event-life" Printer Description Printer's "ippget-event-life" Printer Description attribute (see
attribute (see section 8.1). The Printer MAY return a value section 8.1). The Printer MAY return a value that is larger than
that is larger than the value of the "ippget-event-life" that of the "ippget-event-life" Printer Description attribute
Printer Description attribute provided that the Printer provided that the Printer increases the Event Life for this
increases the Event Life for this Subscription object, so that Subscription object so that Notification Recipients taking account of
Notification Recipients taking account of the larger value and the larger value and polling with a longer interval will not miss
polling with a longer interval will not miss events. Note; events. Note: Implementing such an algorithm requires some hidden
implementing such an algorithm requires some hidden attributes attributes in the Subscription object that are IMPLEMENTATION
in the Subscription object that are IMPLEMENTATION DEPENDENT. DEPENDENT.
If the Printer wants to remain in Event Wait Mode, then the If the Printer wants to remain in Event Wait Mode, then the Printer
Printer MUST NOT return this attribute in the response. MUST NOT return this attribute in the response.
Here is a complete table of combinations of "notify-wait", Here is a complete table of combinations of "notify-wait", "status-
"status-code", "notify-get-interval", and Event Notification code", "notify-get-interval", and Event Notification Attributes
Attributes Groups for Get-Notification initial (Wait and No Groups for Get-Notification initial (Wait and No Wait) Responses and
Wait) Responses and subsequent Event Wait Mode Responses (which subsequent Event Wait Mode Responses (which may stay in Event Wait
may be staying in Event Wait Mode or may be requesting the Mode or may request the Notification Recipient to leave Event Wait
Notification Recipient to leave Event Wait Mode): Mode):
Table 2 - Combinations of "notify-wait", "status-code", and "notify- Table 2. Combinations of "notify-wait", "status-code", and
get-interval" "notify-get-interval"
client sends: Printer returns: Printer Event Client sends: Printer returns: Printer Event
returns: Notification returns: Notification
"notify-wait" "status-code" "notify-get- Attribute "notify-wait" "status-code" "notify-get- Attribute
interval" Groups interval" Groups
1. 'false'* 'successful-ok' MUST return N maybe 1. 'false'* 'successful-ok' MUST return N maybe
2. 'false'* 'not-found' MUST NOT MUST NOT 2. 'false'* 'not-found' MUST NOT MUST NOT
3. 'false'* 'busy' MUST return N MUST NOT 3. 'false'* 'busy' MUST return N MUST NOT
4. 'false'* 'events- MUST NOT 'job- 4. 'false'* 'events- MUST NOT 'job-
complete' completed' complete' completed'
5. 'true' 'successful-ok' MUST NOT MUST 5. 'true' 'successful-ok' MUST NOT MUST
6. 'true' 'successful-ok' MUST return N maybe 6. 'true' 'successful-ok' MUST return N maybe
7. 'true' 'not-found' MUST NOT MUST NOT 7. 'true' 'not-found' MUST NOT MUST NOT
8. 'true' 'busy' MUST return N MUST NOT 8. 'true' 'busy' MUST return N MUST NOT
9. 'true' 'events- MUST NOT 'job- 9. 'true' 'events- MUST NOT 'job-
complete' completed' or complete' completed' or
maybe other maybe other
* 'false' or client omits the "notify-wait" attribute. * 'false' or client omits the "notify-wait" attribute.
Explanation: Explanation:
1-4: client does not request Event Wait Mode 1-4: Client does not request Event Wait Mode.
5-9: client requests Event Wait Mode 5-9: Client requests Event Wait Mode.
2,7: Subscription object not found, or was canceled earlier; 2,7: Subscription object not found, or was canceled earlier;
client should NOT try again. client should NOT try again.
3,8: server busy, tells client to try later; client should try 3,8: Server busy, tells client to try later; client should try
again in N seconds. again in N seconds.
4: client polled after job completed, but before Event Life 4: Client polled after job completed, but before Event Life
expired, and got the 'job-completed' event, so the client expired, and got the 'job-completed' event, so the client
shouldn't bother trying again; client should NOT try again shouldn't bother trying again; client should NOT try
later. again later.
5: Printer returns one or more Event Notifications and is OK 5: Printer returns one or more Event Notifications and is OK
to stay in Event Wait Mode; the client waits for more Event to stay in Event Wait Mode; the client waits for more
Notifications to be returned. Event Notifications to be returned.
6: Printer wants to leave Event Wait mode. Can happen on the 6: Printer wants to leave Event Wait mode. Can happen on
first response (with or without Event Notifications) or happen the first response (with or without Event Notifications)
on a subsequent response with or without Event Notifications; or happen on a subsequent response with or without Event
the client SHOULD try again in N seconds. Notifications; the client SHOULD try again in N seconds.
9: Printer either (1) returns 'job-completed' event or (2) the 9: Either (1) the printer returns 'job-completed' event, or
Subscription Object was canceled by either a Cancel-Job or a (2) the Subscription Object was canceled by either a
Per-Printer Subscription expired without being renewed. For Cancel-Job or a Per-Printer Subscription expired without
case (1), at least one Event Notification MUST be returned, being renewed. For case (1), at least one Event
while for case (2), it is unlikely that any Event Notifications Notification MUST be returned; for case (2), it is
are returned; the client should NOT try again. unlikely that any Event Notifications are returned, and
the client should NOT try again.
5.2.2 printer-up-time (integer(1:MAX)) 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. The attribute at the time when the Printer sends this response. The
Printer MUST return this attribute. Because each Event Printer MUST return this attribute. Because each Event Notification
Notification also contains the value of this attribute when the also contains the value of this attribute when the event occurred,
event occurred, the value of this attribute lets a Notification the value of this attribute lets a Notification Recipient know when
Recipient know when each Event Notification occurred relative each Event Notification occurred relative to the time of this
to the time of this response. response.
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
ntfy]). The matched Event Notifications are all un-expired [RFC3995]). The matched Event Notifications are all un-expired
Event Notification associated with the matched Subscription Event Notifications 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. In other Notification specified in [RFC3995] section 9. In other words,
words, the Printer MUST order these Event Notification groups the Printer MUST order these Event Notification groups in
in ascending time stamp (and sequence number) order for a ascending time stamp (and sequence number) order for a
Subscription object. If Event Notifications for multiple Subscription object. If Event Notifications for multiple
Subscription objects are being returned, the Notification Subscription objects are being returned, the Notification
Events for the next Subscription object follow in ascending Events for the next Subscription object follow in ascending
time stamp order, etc. time stamp order, etc.
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 [RFC3995], 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 identical to those in section 9.1
("Content of Machine Consumable Event Notifications") of [ipp- ("Content of Machine Consumable Event Notifications") of
ntfy] except that each cell in the "Sends" column is a "MUST". [RFC3995], except that each cell in the "Sends" column is a
"MUST".
If more than one Event Notification is being returned and the If more than one Event Notification is being returned and the
status of each is not the same, then the Printer MUST return a status of each is not the same, then the Printer MUST return a
"notify-status-code" attribute in each Event Notification "notify-status-code" attribute in each Event Notification
Attributes group to indicate the differing status values. 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 3. the attributes shown in Table 3.
Table 3 - Attributes in Event Notification Content Table 3. Attributes in Event Notification Content
Source Value Sends Source
Object
notify-subscription-id (integer(1:MAX)) MUST Subscription Source Value Sends Source Object
notify-printer-uri (uri) MUST Subscription
notify-subscribed-event (type2 keyword) MUST Event
Notification
printer-up-time (integer(1:MAX)) * MUST Printer
printer-current-time (dateTime) MUST ** Printer
notify-sequence-number (integer (0:MAX)) MUST Subscription
notify-charset (charset) MUST Subscription
notify-natural-language (naturalLanguage) MUST Subscription
notify-user-data (octetString(63)) MUST *** Subscription
notify-text (text) MUST Event
Notification
attributes from the "notify-attributes" MUST **** Printer
attribute
attributes from the "notify-attributes" MUST **** Job
attribute
attributes from the "notify-attributes" MUST **** Subscription
attribute
* As specified in [ipp-ntfy] section 9, the value of the notify-subscription-id (integer(1:MAX)) MUST Subscription
"printer-up-time" attribute sent in each Event Notification notify-printer-uri (uri) MUST Subscription
MUST be the time at which the Event occurred, not the time at notify-subscribed-event (type2 keyword) MUST Event
which the Event Notification was sent. Notification
printer-up-time (integer(1:MAX)) * MUST Printer
printer-current-time (dateTime) MUST ** Printer
notify-sequence-number (integer (0:MAX)) MUST Subscription
notify-charset (charset) MUST Subscription
notify-natural-language (naturalLanguage) MUST Subscription
notify-user-data (octetString(63)) MUST *** Subscription
notify-text (text) MUST Event
Notification
attributes from the "notify-attributes" MUST **** Printer
attribute
attributes from the "notify-attributes" MUST **** Job
attribute
attributes from the "notify-attributes" MUST **** Subscription
attribute
** The Printer MUST send the "printer-current-time" attribute * As specified in [RFC3995] section 9, the value of the
if and only if it supports the "printer-current-time" attribute "printer-up-time" attribute sent in each Event Notification
on 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
"notify-user-data" attribute, the Printer MUST send an octet- if and only if it supports the "printer-current-time" attribute
string of length 0. on the Printer object.
**** If the "notify-attributes" attribute is present on the *** If the associated Subscription Object does not contain a
Subscription Object, the Printer MUST send all attributes "notify-user-data" attribute, the Printer MUST send an
specified by the "notify-attributes" attribute. Note: if the octet-string of length 0.
Printer doesn't support the "notify-attributes" attribute, it
is not present on the associated Subscription Object.
For Event Notifications for Job Events, the Printer includes **** If the "notify-attributes" attribute is present on the
the additional attributes shown in Table 4. Subscription Object, the Printer MUST send all attributes
specified by the "notify-attributes" attribute. Note: If the
Printer doesn't support the "notify-attributes" attribute, it
is not present on the associated Subscription Object.
Table 4 - Additional Attributes in Event Notification Content for For Event Notifications for Job Events, the Printer includes
Job Events the additional attributes shown in Table 4.
Source Value Sends Source Table 4. Additional Attributes in Event Notification Content for
Object Job Events
job-id (integer(1:MAX)) MUST Job Source Value Sends Source Object
job-state (type1 enum) MUST Job
job-state-reasons (1setOf type2 keyword) MUST Job
job-impressions-completed (integer(0:MAX)) MUST * Job
* The Printer MUST send the "job-impressions-completed" job-id (integer(1:MAX)) MUST Job
attribute in an Event Notification only for the combinations of job-state (type1 enum) MUST Job
Events and Subscribed Events shown in Table 5. job-state-reasons (1setOf type2 keyword) MUST Job
job-impressions-completed (integer(0:MAX)) MUST * Job
* The Printer MUST send the "job-impressions-completed" attribute
in an Event Notification only for the combinations of Events and
Subscribed Events shown in Table 5.
Table 5 - Combinations of Events and Subscribed Events for "job- Table 5. Combinations of Events and Subscribed Events for
impressions-completed" "job-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 6. the additional attributes shown in Table 6.
Table 6 - 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-state-reasons (1setOf type2 keyword) MUST Printer
printer-is-accepting-jobs (boolean) MUST Printer printer-is-accepting-jobs (boolean) MUST Printer
6 Additional Information about Subscription Template Attributes 6. Additional Information about Subscription Template Attributes
The 'ippget' Delivery Method does not define any addition The 'ippget' Delivery Method does not define any addition
Subscription Template attributes. The 'ippget' Delivery Method has Subscription Template attributes and has the conformance requirements
the same conformance requirements for Subscription Template for Subscription Template attributes defined in [RFC3995]. This
attributes as defined in [ipp-ntfy]. This section defines additional section defines additional information about Subscription Template
information about Subscription Template attributes defined in [ipp- attributes defined in [RFC3995].
ntfy].
6.1 notify-pull-method (type2 keyword) 6.1. notify-pull-method (type2 keyword)
This Subscription Template attribute identifies the Pull Delivery This Subscription Template attribute identifies the Pull Delivery
Method to be used for the Subscription Object (see [ipp-ntfy]). In Method to be used for the Subscription Object (see [RFC3995]). To
order to support the 'ippget' Pull Delivery Method defined in this support the 'ippget' Pull Delivery Method defined in this document,
document, the Printer MUST support this attribute with the following the Printer MUST support this attribute with the following keyword
keyword value: value:
'ippget': indicates that the 'ippget' Pull Delivery Method is to 'ippget': Indicates that the 'ippget' Pull Delivery Method is to
be used for this Subscription Object. be used for this Subscription Object.
7 Subscription Description Attributes 7. Subscription Description Attributes
The 'ippget' Delivery Method has the same conformance requirements The 'ippget' Delivery Method has the conformance requirements for
for Subscription Description attributes as defined in [ipp-ntfy]. Subscription Description attributes defined in [RFC3995]. The
The 'ippget' Delivery Method does not define any addition 'ippget' Delivery Method does not define any addition Subscription
Subscription Description attributes. Description attributes.
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-life (integer(15:MAX)) 8.1. ippget-event-life (integer(15:MAX))
This Printer Description attribute specifies the Event Life value This Printer Description attribute specifies the Event Life value
that the Printer assigns to each Event, i.e., the number of seconds that the Printer assigns to each Event; i.e., the number of seconds
after an Event occurs during which a Printer will return that Event after an Event occurs during which a Printer will return that Event
in an Event Notification in a Get-Notifications response. After the 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 Life expires for the Event, the Printer MAY no longer return an
Event Notification for that Event in a Get-Notifications response. 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. The value MUST be 15 or more (at least 15 seconds) 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 and 60 (seconds) is the RECOMMENDED value to align with the PWG Job
Monitoring MIB [RFC2707] jmGeneralJobPersistence and Monitoring MIB [RFC2707] jmGeneralJobPersistence and
jmGeneralAttributePersistence objects. jmGeneralAttributePersistence objects.
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 the 'ippget' Delivery Subscription Object associated with the 'ippget' Delivery Method;
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
the Subscription Object is created, AND Subscription Object is created;
3. the same client or some other client performs a Get- 3. the same client or some other client performs a Get-Notifications
Notifications operation such that the client is connected N operation so that the client is connected N seconds after the Job
seconds after the Job Creation operation. 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. Note: The client MUST initiate the Get- in the Printer. Note: The client MUST initiate the Get-
Notifications a time that is sufficiently less that N seconds to Notifications at a time that is sufficiently less that N seconds to
account for network latency so that it is connected to the Printer account for network latency so that it is connected to the Printer
before N seconds elapses. before N seconds elapses.
If a Printer supports the 'ippget' Delivery Method, it MUST keep If a Printer supports the 'ippget' Delivery Method, it MUST keep
'completed', 'canceled', or 'aborted' Job objects in the Job 'completed', 'canceled', or 'aborted' Job objects in the Job
Retention and/or Job History phases for at least as long as this Retention and/or Job History phases for at least as long as this
attribute's value. The Printer MAY retain jobs longer that this attribute's value. The Printer MAY retain jobs longer that this
value. See [RFC2911] section 4.3.7.1 and the discussion in [ipp- value. See [RFC2911], section 4.3.7.1, and the discussion in
ntfy] 'job-completed' event) that explains that a Notification [RFC3995] (regarding the 'job-completed' event). The latter explains
Recipients can query the Job after receiving a 'job-completed' Event that a Notification Recipient can query the Job after receiving a
Notification in order to find out other information about the job 'job-completed' Event Notification in order to find out other
that is 'completed', 'aborted', or 'canceled'. However, this information about the job that is 'completed', 'aborted', or
attribute has no effect on the Cancel-Subscription operation which 'canceled'. However, this attribute has no effect on the Cancel-
deletes the Subscription object immediately, whether or not it Subscription operation, which deletes the Subscription object
contain the "notify-pull-method" attribute with the 'ippget' keyword immediately whether or not it contains the "notify-pull-method"
value. Immediately thereafter, subsequent Get-Notifications attribute with the 'ippget' keyword value. Immediately thereafter,
Responses MUST NOT contain Event Notifications associated with the subsequent Get-Notifications Responses MUST NOT contain Event
canceled Subscription object. Notifications 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 defined in [ipp-ntfy]. Description attributes as defined in [RFC3995].
9.1 notify-pull-method-supported (1setOf type2 keyword) 9.1. notify-pull-method-supported (1setOf type2 keyword)
The following keyword value for the "notify-pull-method-supported" The following keyword value for the "notify-pull-method-supported"
attribute is added in order to support the new Delivery Method attribute is added in order to support the new Delivery Method
defined in this document: defined in this document:
'ippget' - The IPP Notification Pull Delivery Method defined in 'ippget': The IPP Notification Pull Delivery Method defined in
this document. this document.
9.2 operations-supported (1setOf type2 enum) 9.2. operations-supported (1setOf type2 enum)
Table 7 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 7 - 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 code is defined as an extension for this The following status code is defined as an extension for this
Delivery Method and is returned as the status code of the Get- Delivery Method and is returned as the status code of the Get-
Notifications operation in Group 1 or Group 3 to N (see section 5.2). Notifications operation in Group 1 or Group 3 to N (see section 5.2).
10.1 successful-ok-events-complete (0x0007) 10.1. successful-ok-events-complete (0x0007)
The Printer MUST return the 'successful-ok-events-complete' status The Printer MUST return the 'successful-ok-events-complete' status
code to indicate when this Get-Notifications response is the last code to indicate when this Get-Notifications response is the last
response for a Subscription object, whether or not there are Event response for a Subscription object, whether or not there are Event
Notifications being returned. This condition occurs for Event Wait Notifications being returned. This condition occurs for Event Wait
Mode with Notification Recipients waiting for responses when the Mode with Notification Recipients waiting for responses when (1) the
Subscription Object is: (1) canceled with a Cancel-Subscription Subscription Object is canceled with a Cancel-Subscription operation,
operation, (2) deleted when the Per-Printer Subscription lease time (2) the Subscription object is deleted, when the Per-Printer
expires, or (3) when the 'job-completed' event occurs for a Per-Job Subscription lease time expires, or (3) the 'job-completed' event
Subscription. This condition also occurs for a Get-Notifications occurs for a Per-Job Subscription. This condition also occurs for a
request that a Notification Recipient makes after the job completes, Get-Notifications request that a Notification Recipient makes after
but before the Event Life expires. the job completes, but before the Event Life expires.
11 Encoding and Transport 11. 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 after the
Response (see [RFC2911]). In a Get-Notifications Response, each Get-Jobs Response (see [RFC2911]). In a Get-Notifications Response,
Event Notification Attributes Group MUST start with an 'event- each 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]), and end with an 'end-of- Additional Attribute Tags" in [RFC3995]), and end with an 'end-of-
attributes-tag'. In addition, for Event Wait Mode the multi- attributes-tag'. In addition, for Event Wait Mode the multi-
part/related is used to separate each multiple response (in time) to part/related is used to separate each multiple 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. encoding), as with any operation response.
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 MUST return the response as an request, the Printer 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.
type. When one or more additional Events occur, the Printer When one or more additional Events occur, the Printer returns
returns each as an additional Event Notification Group using a each as an additional Event Notification Group using a separate
separate application/ipp part under the multi-part/related type. 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'),
'true'), but the Printer does not wish to honor the request in but the Printer does not wish to honor the request in the initial
the initial response but wants the client explicitly poll for response and wants the client explicitly polled for Event
Event Notifications, the Printer MUST return the "notify-get- Notifications, the Printer MUST return the "notify-get-interval"
interval" operation attribute (see section 5.2.1). The Printer operation attribute (see section 5.2.1). The Printer returns the
returns the response as an application/ipp part which MAY be response as an application/ipp part that MAY be inside an multi-
inside an multi-part/related type. The client MUST accept this part/related type. The client MUST accept this response and
response and re-issue the Get-Notifications request in the reissue the Get-Notifications request in the future indicated by
future indicated by the value of the "notify-get-interval" the value of the "notify-get-interval" attribute value.
attribute value..
4. If the client requested Event Wait Mode ("notify-wait" = 4. If the client requested Event Wait Mode ("notify-wait" = 'true'),
'true'), and the Printer initially honored the request, but and the Printer initially honored the request but later wishes to
later wishes to leave Event Wait Mode, the Printer MUST return leave Event Wait Mode, the Printer MUST return the "notify-get-
the "notify-get-interval" operation attribute (see section interval" operation attribute (see section 5.2.1). The Printer
5.2.1). The Printer returns the response as an application/ipp returns the response as an application/ipp part that MUST be
part which MUST be inside an multi-part/related type. inside an multi-part/related type.
NOTE: if a Notification Recipient fails to receive a response, it can NOTE: If a Notification Recipient fails to receive a response, it
ask the Printer for the same Event Notifications again. The can ask the Printer for the same Event Notifications again. The
Notification Recipient will receive the same Event Notifications as Notification Recipient will receive the same Event Notifications that
it should have received the first time except for those Event it should have received the first time, except for those Event
Notifications that have expired in the meantime. Notifications that have expired in the meantime.
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.
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 the following [RFC2910] for the Get-Notifications operation with the following
extension allocated in [ipp-ntfy]: extension, allocated in [RFC3995]:
Table 8 - 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"
12 Conformance Requirements 12. Conformance Requirements
This section lists the conformance requirements for clients and This section lists the conformance requirements for clients and
Printers. Printers.
12.1 Conformance for IPP Printers 12.1. Conformance for IPP Printers
It is OPTIONAL for a Printer to support IPP Notifications as defined It is OPTIONAL for a Printer to support IPP Notifications as defined
in [ipp-ntfy]. However, if a Printer supports IPP Notifications, the in [RFC3995]. However, if a Printer supports IPP Notifications, the
Printer MUST support the 'ippget' Delivery Method as defined in this Printer MUST support the 'ippget' Delivery Method, as defined in this
document as one of its Delivery Methods. IPP Printers that conform document, as one of its Delivery Methods. IPP Printers that conform
to this specification: to this specification
1. MUST meet the conformance requirements defined in [ipp-ntfy] for 1. MUST meet the conformance requirements defined in [RFC3995] for a
a Pull Delivery Method; Pull Delivery Method;
2. MUST support the Get-Notifications operation defined in section 2. MUST support the Get-Notifications operation defined in section
5, including Event Wait Mode; 5, including Event Wait Mode;
3. MUST support the Subscription Template object attributes as 3. MUST support the Subscription Template object attributes, as
defined in section 6; defined in section 6;
4. MUST support the Subscription Description object attributes as 4. MUST support the Subscription Description object attributes, as
defined in section 7; defined in section 7;
5. MUST support the "ippget-event-life" Printer Description 5. MUST support the "ippget-event-life" Printer Description
attribute defined in section 8.1, including retaining jobs in attribute defined in section 8.1, including retaining jobs in the
the Job Retention and/or Job History phases for at least as long Job Retention and/or Job History phases for at least as long as
as the value specified by the Printer's "ippget-event-life"; the value specified by the Printer's "ippget-event-life";
6. MUST support the additional values for IPP/1.1 Printer 6. MUST support the additional values for IPP/1.1 Printer
Description attributes defined in section 9; Description attributes defined in section 9;
7. MUST support the 'successful-ok-events-complete' status code as 7. MUST support the 'successful-ok-events-complete' status code, as
described in section 10.1; described in section 10.1;
8. MUST listen for the IPP Get-Notifications operation requests on 8. 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 9. SHOULD NOT listen for IPP Get-Notifications operation requests on
on any other port, unless explicitly configured by system any other port, unless explicitly configured by system
administrators or site policies. administrators or site policies; and
10. MUST meet the security conformance requirements as stated in 10. MUST meet the security conformance requirements stated in section
section 18.4. 18.4.
12.2 Conformance for IPP Clients 12.2. Conformance for IPP Clients
It is OPTIONAL for an IPP Client to support IPP Notifications as It is OPTIONAL for an IPP Client to support IPP Notifications as
defined in [ipp-ntfy]. However, if a client supports IPP defined in [RFC3995]. However, if a client supports IPP
Notifications, the client MUST support the 'ippget' Delivery Method Notifications, the client MUST support the 'ippget' Delivery Method
as defined in this document as one of its Delivery Methods. IPP as defined in this document as one of its Delivery Methods. IPP
Clients that conform to this specification: Clients that conform to this specification:
1. MUST create Subscription Objects by sending Subscription 1. MUST create Subscription Objects by sending Subscription Creation
Creation operation requests containing the "notify-pull-method" operation requests containing the "notify-pull-method" attribute
attribute (as opposed to the "notify-recipient-uri" attribute) (as opposed to the "notify-recipient-uri" attribute) using the
using the 'ippget' keyword value (see sections 6.1 and 15.2); 'ippget' keyword value (see sections 6.1 and 15.2);
2. MUST send IPP Get-Notifications operation requests (see section 2. MUST send IPP Get-Notifications operation requests (see section
5.1) via the port specified in the associated 'ipp' URL (if 5.1) via the port specified in the associated 'ipp' URL (if
present) or otherwise via IANA assigned well-known port 631; present) or otherwise via IANA-assigned well-known port 631;
3. 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]; and
4. MUST meet the security conformance requirements as stated in
section 18.5.
13 Normative References 4. MUST meet the security conformance requirements stated in section
18.5.
[ipp-ntfy] 13. Normative References
Herriot, R., and T. Hastings, "Internet Printing Protocol/1.1: IPP
Event Notifications and Subscriptions", <draft-ietf-ipp-not-spec-
12.txt>, June 21, 2004.
[RFC2119] [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
S. Bradner, "Key words for use in RFCs to Indicate Requirement Requirement Levels", BCP 14, RFC 2119, March 1997.
Levels", RFC 2119 , March 1997
[RFC2910] [RFC2910] Herriot, R., Butler, S., Moore, P., Turner, R., and J.
Herriot, R., Butler, S., Moore, P., and R. Tuner, "Internet Wenn, "Internet Printing Protocol/1.1: Encoding and
Printing Protocol/1.1: Encoding and Transport", RFC 2910, September Transport", RFC 2910, September 2000.
2000.
[RFC2911] [RFC2911] Hastings, T., Herriot, R., deBry, R., Isaacson, S., and
deBry, R., Hastings, T., Herriot, R., Isaacson, S., and P. Powell, P. Powell, "Internet Printing Protocol/1.1: Model and
"Internet Printing Protocol/1.1: Model and Semantics", RFC 2911, Semantics", RFC 2911, September 2000.
September 2000.
14 Informative References [RFC3995] Herriot, R. and T. Hastings, "Internet Printing Protocol
(IPP): Event Notifications and Subscriptions", RFC 3995,
March 2005.
[notify-req] 14. Informative References
Hastings, T., deBry, R., and H. Lewis, "Internet Printing Protocol
(IPP): Requirements for IPP Notifications", <draft-ietf-ipp-not-
07.txt>, June 21, 2004.
[RFC2565] [RFC2565] Herriot, R., Butler, S., Moore, P., and R. Turner,
Herriot, R., Butler, S., Moore, P., and R. Turner, "Internet "Internet Printing Protocol/1.0: Encoding and
Printing Protocol/1.0: Encoding and Transport", RFC 2565, April Transport", RFC 2565, April 1999.
1999.
[RFC2566] [RFC2566] deBry, R., Hastings, T., Herriot, R., Isaacson, S., and
R. deBry, T. Hastings, R. Herriot, S. Isaacson, and P. Powell, P. Powell, "Internet Printing Protocol/1.0: Model and
"Internet Printing Protocol/1.0: Model and Semantics", RFC 2566, Semantics", RFC 2566, April 1999.
April 1999.
[RFC2567] [RFC2567] Wright, F., "Design Goals for an Internet Printing
Wright, D., "Design Goals for an Internet Printing Protocol", RFC Protocol", RFC 2567, April 1999.
2567, April 1999.
[RFC2568] [RFC2568] Zilles, S., "Rationale for the Structure of the Model
Zilles, S., "Rationale for the Structure and Model and Protocol for and Protocol for the Internet Printing Protocol", RFC
the Internet Printing Protocol", RFC 2568, April 1999. 2568, April 1999.
[RFC2569] [RFC2569] Herriot, R., Hastings, T., Jacobs, N., and J. Martin,
Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between "Mapping between LPD and IPP Protocols", RFC 2569, April
LPD and IPP Protocols", RFC 2569, April 1999. 1999.
[RFC2616] [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P. Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1", Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.
RFC 2616, June 1999.
[RFC2707] [RFC2707] Bergman, R., Hastings, T., Isaacson, S., and H. Lewis,
Bergman, R., Hastings, T., Isaacson, S., and H. Lewis, "Job "Job Monitoring MIB - V1.0", RFC 2707, November 1999.
Monitoring MIB - V1.0", November 1999.
[RFC3196] [RFC3196] Hastings, T., Manros, C., Zehler, P., Kugler, C., and H.
Hastings, T., Manros, C., Zehler, P., Kugler, C., and H. Holst, Holst, "Internet Printing Protocol/1.1: Implementor's
"Internet Printing Protocol/1.1: Implementer's Guide", RFC3196, Guide", RFC 3196, November 2001.
November 2001.
15 IANA Considerations [RFC3997] Hastings, T., Ed., deBry, R., and H. Lewis, "Internet
Printing Protocol (IPP): Requirements for IPP
Notifications", RFC 3997, March 2005.
This section contains the exact information for IANA to add to the 15. IANA Considerations
IPP Registries according to the procedures defined in RFC 2911
[RFC2911] section 6. The resulting registrations will be published
in the http://www.iana.org/assignments/ipp-registrations registry.
Note to RFC Editors: Replace RFC NNNN below with the RFC number This section contains the exact information that the IANA has added
for this document, so that it accurately reflects the content of to the IPP Registries according to the procedures defined in
the information for the IANA Registry. [RFC2911], section 6. These registrations have been published in the
http://www.iana.org/assignments/ipp-registrations registry.
15.1 Attribute Registrations 15.1. Attribute Registrations
The following table lists the attributes defined in this document. The following table lists the attributes defined in this document.
This is to be registered according to the procedures in RFC 2911 This has been registered according to the procedures in RFC 2911
[RFC2911] section 6.2. [RFC2911] section 6.2.
Printer Description attributes: Reference Section Printer Description attributes: Reference Section
------------------------------- --------- ------- ------------------------------- --------- -------
ippget-event-life (integer(15:MAX)) [RFCNNNN] 8.1 ippget-event-life (integer(15:MAX)) [RFC3996] 8.1
15.2 Delivery Method and Additional keyword attribute value 15.2. Delivery Method and Additional Keyword Attribute Value
registrations for existing attributes Registrations for Existing Attributes
This section lists additional keyword attribute value registrations This section lists additional keyword attribute value registrations
for use with existing attributes defined in other documents. These for use with existing attributes defined in other documents. These
are to be registered according to the procedures in RFC 2911 have been registered according to the procedures in [RFC2911],
[RFC2911] section 6.1. According to [ipp-ntfy] section 24.7.3, Pull section 6.1. According to [RFC3995], section 24.7.3, Pull Delivery
Delivery Method registrations are the keyword attribute value Method registrations are the keyword attribute value registrations
registrations for the "notify-pull-method" and "notify-pull-method- for the "notify-pull-method" and "notify-pull-method-supported"
supported" attributes. attributes.
Attribute (attribute syntax) Attribute (attribute syntax)
Values Reference Section Values Reference Section
----------------------- --------- ------- ----------------------- --------- -------
notify-pull-method (type2 keyword) [ipp-ntfy] 5.3.2 notify-pull-method (type2 keyword) [RFC3995] 5.3.2
notify-pull-method-supported (1setOf type2 keyword) notify-pull-method-supported (1setOf type2 keyword)
[ipp-ntfy] 5.3.2.1 [RFC3995] 5.3.2.1
ippget [RFCNNNN] 9.1 ippget [RFC3996] 9.1
15.3 Additional enum attribute values 15.3. Additional Enum Attribute Values
The following table lists the enum attribute values defined in this The following table lists the enum attribute values defined in this
document. These are to be registered according to the procedures in document. These have been registered according to the procedures in
RFC 2911 [RFC2911] section 6.1. [RFC2911], section 6.1.
Attribute (attribute syntax) Attribute (attribute syntax)
Value Name Reference Section Value Name Reference Section
------ ----------------------------- --------- ------- ------ ----------------------------- --------- -------
operations-supported (type2 enum) [RFC2911] 4.4.15 operations-supported (1setOf type2 enum) [RFC2911] 4.4.15
0x001C Get-Notifications [RFCNNNN] 9.2 0x001C Get-Notifications [RFC3996] 9.2
15.4 Operation Registrations 15.4. Operation Registrations
The following table lists the operations defined in this document. The following table lists the operations defined in this document.
This is to be registered according to the procedures in RFC 2911 This has been registered according to the procedures in RFC 2911
[RFC2911] section 6.4. [RFC2911] section 6.4.
Operations: Reference Section Operations: Reference Section
----------- --------- ------- ----------- --------- -------
Get-Notifications [RFCNNNN] 5 Get-Notifications [RFC3996] 5
15.5 Status code Registrations 15.5. Status Code Registrations
The following table lists the status codes defined in this document. The following table lists the status codes defined in this document.
This is to be registered according to the procedures in RFC 2911 This has been registered according to the procedures in [RFC2911],
[RFC2911] section 6.6. section 6.6.
Status codes: Reference Section Status codes: Reference Section
------------- --------- ------- ------------- --------- -------
successful-ok-events-complete (0x0007) [RFCNNNN] 10.1 successful-ok-events-complete (0x0007) [RFC3996] 10.1
16 Intellectual Property
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in RFC 2028. Copies of
claims of rights made available for publication and any assurances of
licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such
proprietary rights by implementers or users of this specification can
be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
17 Internationalization Considerations 16. 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 [RFC3995].
In addition, when the client receives the Get-Notifications response, In addition, when the client receives the Get-Notifications response,
it is expected to localize the attributes that have the 'keyword' it is expected to localize the attributes that have the 'keyword'
attribute syntax according to the charset and natural language attribute syntax according to the charset and natural language
requested in the Get-Notifications request. requested in the Get-Notifications request.
18 Security Considerations 17. Security Considerations
The IPP Model and Semantics document [RFC2911 section 8] discusses The IPP Model and Semantics document [RFC2911, section 8] discusses
high-level security requirements (Client Authentication, Server high-level security requirements (Client Authentication, Server
Authentication and Operation Privacy). The IPP Transport and Authentication and Operation Privacy). The IPP Transport and
Encoding document [RFC2910 section 8] discusses the security Encoding document [RFC2910, section 8] discusses the security
requirements for the IPP protocol. Client Authentication is the requirements for the IPP protocol. Client Authentication is the
mechanism by which the client proves its identity to the server in a mechanism by which the client proves its identity to the server in a
secure manner. Server Authentication is the mechanism by which the secure manner. Server Authentication is the mechanism by which the
server proves its identity to the client in a secure manner. server proves its identity to the client in a secure manner.
Operation Privacy is defined as a mechanism for protecting operations Operation Privacy is defined as a mechanism for protecting operations
from eavesdropping. from eavesdropping.
The 'ippget' Delivery Method with its Get-Notifications operations The 'ippget' Delivery Method with its Get-Notifications operations
leverages the security mechanism that are used in IPP/1.1 [RFC2910 leverages the security mechanism that are used in IPP/1.1 [RFC2910
and RFC2911] without adding any additional security mechanisms in and RFC2911] without adding any additional security mechanisms in
order to maintain the same security support as IPP/1.1. order to maintain the same security support as IPP/1.1.
The access control model for the Get-Notifications operation defined The access control model for the Get-Notifications operation defined
in this document is the same as the access control model for the Get- in this document is the same as the access control model for the
Job-Attributes operation (see [RFC2911] section 3.2.6). The primary Get-Job-Attributes operation (see [RFC2911], section 3.2.6). The
difference is that a Get-Notifications operation is directed at primary difference is that a Get-Notifications operation is directed
Subscription Objects rather than at Job objects, and a returned at Subscription Objects rather than at Job objects, and a returned
attribute group contains Event Notification attributes rather than attribute group contains Event Notification attributes rather than
Job object attributes. Job object attributes.
18.1 Notification Recipient client access rights 17.1. Notification Recipient Client Access Rights
The Notification Recipient client MUST have the following access The Notification Recipient client MUST have the following access
rights to the Subscription object(s) targeted by the Get- rights to the Subscription object(s) targeted by the Get-
Notifications operation request: Notifications operation request:
The authenticated user (see [RFC2911] section 8.3) performing this The authenticated user (see [RFC2911], section 8.3) performing
operation MUST be (1) the owner of each Subscription Object this operation MUST be (1) the owner of each Subscription Object
identified by the "notify-subscription-ids" operation attribute identified by the "notify-subscription-ids" operation attribute
(see section 5.1.1), (2) an operator or administrator of the (see section 5.1.1), (2) an operator or administrator of the
Printer (see [RFC2911] Sections 1 and 8.5), or (3) be otherwise Printer (see [RFC2911], sections 1 and 8.5), or (3) otherwise
authorized by the Printer's administrator-configured security authorized by the Printer's administrator-configured security
policy to request Event Notifications from the target Subscription policy to request Event Notifications from the target Subscription
Object(s). Furthermore, the Printer's security policy MAY limit Object(s). Furthermore, the Printer's security policy MAY limit
the attributes returned by the Get-Notifications operation, in a the attributes returned by the Get-Notifications operation, in a
manner similar to the Get-Job-Attributes operation (see [RFC2911] manner similar to that of the Get-Job-Attributes operation (see
end of section 3.3.4.2). [RFC2911], end of section 3.3.4.2).
18.2 Printer security threats 17.2. Printer Security Threats
Because the Get-Notifications operation is sent in the same direction Because the Get-Notifications operation is sent in the same direction
as Job Creation operations, usually by the same client, this Event as are Job Creation operations, usually by the same client, this
Notification Delivery Method poses no additional authentication, Event Notification Delivery Method poses no additional
authorization, privacy, firewall, or port assignment issues above authentication, authorization, privacy, firewall, or port assignment
those for the IPP Get-Job-Attributes and Get-Printer-Attributes issues above those for the IPP Get-Job-Attributes and Get-Printer-
operations (see [RFC2911] sections 3.2.6 and 3.2.5). Attributes operations (see [RFC2911], sections 3.2.6 and 3.2.5).
18.3 Notification Recipient security threats 17.3. Notification Recipient Security Threats
Unwanted Events Notifications (spam): Unlike Push Event Notification Unwanted Events Notifications (spam): Unlike Push Event Notification
Delivery Methods in which the IPP Printer initiates the Event Delivery Methods in which the IPP Printer initiates the Event
Notification, with the Pull Delivery Method defined in this document, Notification, with the Pull Delivery Method defined in this document,
the Notification Recipient is the client who initiates the Get- the Notification Recipient is the client that initiates the Get-
Notifications operation (see section 5). Therefore, there is no Notifications operation (see section 5). Therefore, with this method
chance of "spam" notifications with this method. there is no chance of "spam" notifications.
Note: when a client stays connected to a Printer using the Event Note: When a client stays connected to a Printer by using the Event
Wait Mode (see section 5.1.3) in order to receive Event Notifications Wait Mode (see section 5.1.3) in order to receive Event Notifications
as they occur, such a client can close down the IPP connection at any as they occur, it can close down the IPP connection at any time and
time, and so can avoid future unwanted Event Notifications at any so can avoid future unwanted Event Notifications at any time.
time.
It is true that client has control about whether to ask for Event It is true that the client has control over whether to ask for Event
Notifications. However, if the client subscribes to an event, and Notifications. However, if the client subscribes to an event and
does a Get-Notifications request, the client gets all events for the does a Get-Notifications request, it gets all events for the
Subscription Object in the sequence number range (see section 5.1.2), Subscription Object in the sequence number range (see section 5.1.2),
not just the ones the client wants. If a client subscribes to a Per- not just those it wants. If a client subscribes to a Per-Printer
Printer Subscription job event, such as 'job-completed', and someone Subscription job event, such as 'job-completed', and someone then
then starts and cancels thousands of jobs, the client would have to starts and cancels thousands of jobs, the client would have to
receive these events in addition to the ones the client is interested receive these events in addition to those it is interested in. A
in. A client can protect itself better by subscribing to his own client can protect itself better by subscribing to its own jobs by
jobs using a Per-Job Subscription, rather than creating a Per-Printer using a Per-Job Subscription, rather than create a Per-Printer
subscription whose Job events apply to all jobs. subscription whose Job events apply to all jobs.
18.4 Security requirements for Printers 17.4. Security Requirements for Printers
For the Get-Notifications operation defined in this document, the For the Get-Notifications operation defined in this document, the
same Printer conformance requirements apply for supporting and using same Printer conformance requirements apply for supporting and using
Client Authentication, Server Authentication and Operation Privacy as Client Authentication, Server Authentication and Operation Privacy as
stated in [RFC2910] section 8 for all IPP operations. stated in [RFC2910] section 8 for all IPP operations.
18.5 Security requirements for clients 17.5. Security Requirements for Clients
For the Get-Notifications operation defined in this document, the For the Get-Notifications operation defined in this document, the
same client conformance requirements apply for supporting and using same client conformance requirements apply for supporting and using
Client Authentication, Server Authentication and Operation Privacy as Client Authentication, Server Authentication, and Operation Privacy
stated in [RFC2910] section 8 for all IPP operations. as stated in [RFC2910], section 8, for all IPP operations.
19 Contributors 18. Description of Base IPP Documents (Informative)
The base set of IPP documents includes the following:
Design Goals for an Internet Printing Protocol [RFC2567]
Rationale for the Structure and Model and Protocol for the Internet
Printing Protocol [RFC2568]
Internet Printing Protocol/1.1: Model and Semantics [RFC2911]
Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]
Internet Printing Protocol/1.1: Implementer's Guide [RFC3196]
Mapping between LPD and IPP Protocols [RFC2569]
"Design Goals for an Internet Printing Protocol" takes a broad look
at distributed printing functionality, and it enumerates real-life
scenarios that help clarify the features that need to be included in
a printing protocol for the Internet. It identifies requirements for
three types of users: end users, operators, and administrators. It
calls out a subset of end user requirements that are satisfied in
IPP/1.0 [RFC2566, RFC2565]. A few OPTIONAL operator operations have
been added to IPP/1.1.
"Rationale for the Structure and Model and Protocol for the Internet
Printing Protocol" describes IPP from a high-level view, defines a
roadmap for the various documents that form the suite of IPP
specification documents, and gives background and rationale for the
IETF working group's major decisions.
"Internet Printing Protocol/1.1: Model and Semantics" describes a
simplified model with abstract objects, their attributes, and their
operations that are independent of encoding and transport. It
introduces a Printer and a Job object. The Job object optionally
supports multiple documents per Job. It also addresses security,
internationalization, and directory issues.
"Internet Printing Protocol/1.1: Encoding and Transport" is a formal
mapping of the abstract operations and attributes defined in the
model document onto HTTP/1.1 [RFC2616]. It defines the encoding
rules for a new Internet MIME media type called "application/ipp".
This document also defines the rules for transporting over HTTP a
message body whose Content-Type is "application/ipp". This document
defines the 'ipp' scheme for identifying IPP printers and jobs.
"Internet Printing Protocol/1.1: Implementer's Guide" gives insight
and advice to implementers of IPP clients and IPP objects. It is
intended to help them understand IPP/1.1 and some of the
considerations that may assist them in the design of their client
and/or IPP object implementations. For example, a typical order of
processing requests is given, including error checking. Motivation
for some of the specification decisions is also included.
"Mapping between LPD and IPP Protocols" gives some advice to
implementers of gateways between IPP and LPD (Line Printer Daemon)
implementations.
19. Contributors
Carl Kugler and Harry Lewis contributed the basic idea of in-band Carl Kugler and Harry Lewis contributed the basic idea of in-band
"smart polling" coupled with multiple responses for a single "smart polling" coupled with multiple responses for a single
operation on the same connection, one response for each event as it operation on the same connection, with one response for each event as
occurs. Without their continual persuasion, we would not have it occurs. Without their continual persuasion, we would not have
arrived at this Delivery Method specification and would not have been arrived at this Delivery Method specification and would not have been
able to agree on a single REQUIRED Delivery Method for IPP. able to agree on a single REQUIRED Delivery Method for IPP.
Carl Kugler Carl Kugler
IBM IBM Corporation
P.O. Box 1900 6300 Diagonal Highway
Boulder, CO 80301-9191 Boulder, CO 80301
Phone:
Fax:
e-mail: kugler@us.ibm.com
20 Authors' Addresses EMail: kugler@us.ibm.com
Authors' Addresses
Robert Herriot Robert Herriot
Global Workflow Solutions Global Workflow Solutions
706 Colorado Ave. 706 Colorado Ave.
Palo Alto, CA 94303 Palo Alto, CA 94303
Phone: 650-324-4000 Phone: 650-324-4000
email: bob@herriot.com EMail: bob@herriot.com
Thomas N. Hastings Thomas N. Hastings
Xerox Corporation Xerox Corporation
737 Hawaii St. ESAE 231 710 S Aviation Blvd. ESAE 242
El Segundo CA 90245 El Segundo CA 90245
Phone: 310-333-6413 Phone: 310-333-6413
Fax: 310-333-5514 Fax: 310-333-6342
email: hastings@cp10.es.xerox.com EMail: hastings@cp10.es.xerox.com
Harry Lewis Harry Lewis
IBM IBM Corporation
P.O. Box 1900 6300 Diagonal Hwy
Boulder, CO 80301-9191 Boulder, CO 80301
Phone: 303-924-5337 Phone: (303) 924-5337
FAX: EMail: harryl@us.ibm.com
e-mail: harryl@us.ibm.com
21 Description of Base IPP documents (Informative) Full Copyright Statement
The base set of IPP documents includes: Copyright (C) The Internet Society (2005).
Design Goals for an Internet Printing Protocol [RFC2567] This document is subject to the rights, licenses and restrictions
Rationale for the Structure and Model and Protocol for the Internet contained in BCP 78, and except as set forth therein, the authors
Printing Protocol [RFC2568] retain all their rights.
Internet Printing Protocol/1.1: Model and Semantics [RFC2911]
Internet Printing Protocol/1.1: Encoding and Transport [RFC2910]
Internet Printing Protocol/1.1: Implementer's Guide [RFC3196]
Mapping between LPD and IPP Protocols [RFC2569]
The "Design Goals for an Internet Printing Protocol" document takes a This document and the information contained herein are provided on an
broad look at distributed printing functionality, and it enumerates "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
real-life scenarios that help to clarify the features that need to be OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
included in a printing protocol for the Internet. It identifies ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
requirements for three types of users: end users, operators, and INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
administrators. It calls out a subset of end user requirements that INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
are satisfied in IPP/1.0. A few OPTIONAL operator operations have WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
been added to IPP/1.1.
The "Rationale for the Structure and Model and Protocol for the
Internet Printing Protocol" document describes IPP from a high level
view, defines a roadmap for the various documents that form the suite
of IPP specification documents, and gives background and rationale
for the IETF working group's major decisions.
The "Internet Printing Protocol/1.1: Model and Semantics" document
describes a simplified model with abstract objects, their attributes,
and their operations that are independent of encoding and transport.
It introduces a Printer and a Job object. The Job object optionally
supports multiple documents per Job. It also addresses security,
internationalization, and directory issues.
The "Internet Printing Protocol/1.1: Encoding and Transport" document
is a formal mapping of the abstract operations and attributes defined
in the model document onto HTTP/1.1 [RFC2616]. It defines the
encoding rules for a new Internet MIME media type called
"application/ipp". This document also defines the rules for
transporting over HTTP a message body whose Content-Type is
"application/ipp". This document defines the 'ipp' scheme for
identifying IPP printers and jobs.
The "Internet Printing Protocol/1.1: Implementer's Guide" document
gives insight and advice to implementers of IPP clients and IPP
objects. It is intended to help them understand IPP/1.1 and some of
the considerations that may assist them in the design of their client
and/or IPP object implementations. For example, a typical order of
processing requests is given, including error checking. Motivation
for some of the specification decisions is also included.
The "Mapping between LPD and IPP Protocols" document gives some
advice to implementers of gateways between IPP and LPD (Line Printer
Daemon) implementations.
22 Full Copyright Statement Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
ipr@ietf.org.
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Acknowledgement Acknowledgement
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
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