draft-ietf-ipp-notify-get-00.txt   draft-ietf-ipp-notify-get-01.txt 
INTERNET-DRAFT Robert Herriot (editor) INTERNET-DRAFT Robert Herriot (editor)
<draft-ietf-ipp-notify-get-00.txt> Xerox Corp. <draft-ietf-ipp-notify-get-01.txt> Xerox Corp.
Carl Kugler Carl Kugler
IBM, Corp. IBM, Corp.
Harry Lewis Harry Lewis
IBM, Corp. IBM, Corp.
September 18, 2000 November 16, 2000
Internet Printing Protocol (IPP): Internet Printing Protocol (IPP):
The 'ippget' Event Notifications Delivery Method The 'ippget' Delivery Method for Event Notifications
Copyright (C) The Internet Society (2000). All Rights Reserved. Copyright (C) The Internet Society (2000). All Rights Reserved.
Status of this Memo: Status of this Memo:
This document is an Internet-Draft and is in full conformance with all This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of [rfc2026]. Internet-Drafts are working provisions of Section 10 of [rfc2026]. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups. Note that other groups may also distribute working its working groups. Note that other groups may also distribute working
documents as Internet-Drafts. documents as Internet-Drafts.
skipping to change at page 1, line 36 skipping to change at page 1, line 36
or to cite them other than as "work in progress". or to cite them other than as "work in progress".
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed as The list of Internet-Draft Shadow Directories can be accessed as
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
Abstract Abstract
The notification extension document [ipp-ntfy] defines operations that a The notification extension document [ipp-ntfy] defines operations that
client can perform in order to create Subscription Objects in a Printer a client can perform in order to create Subscription Objects in a
and carry out other operations on them. A Subscription Object represents Printer and carry out other operations on them. A Subscription Object
a Subscription abstraction. The Subscription Object specifies that when represents a Subscription abstraction. The Subscription Object
one of the specified Events occurs, the Printer sends an asynchronous specifies that when one of the specified Events occurs, the Printer
Event Notification to the specified Notification Recipient via the sends an asynchronous Event Notification to the specified Notification
specified Delivery Method (i.e., protocol). Recipient via the specified Delivery Method (i.e., protocol).
The notification extension document [ipp-ntfy] specifies that each The notification extension document [ipp-ntfy] specifies that each
Delivery Method is defined in another document. This document is one Delivery Method is defined in another document. This document is one
such document, and it specifies the 'ippget' delivery method. such document, and it specifies the 'ippget' delivery method.
The 'ippget' Delivery Method is a 'pull and push' Delivery Method. That The 'ippget' Delivery Method is a 'pull and push' Delivery Method. That
is, the Printer saves Event Notification for a period of time and is, the Printer saves Event Notification for a period of time and
expects the Notification Recipient to fetch the Event Notifications (the expects the Notification Recipient to fetch the Event Notifications
pull part). The Printer continues to send Event Notifications to the (the pull part). The Printer continues to send Event Notifications to
Notification Recipient as Events occur (the push part) if the client has the Notification Recipient as Events occur (the push part) if the
selected the option to wait for additional Event Notifications. client has selected the option to wait for additional Event
Notifications.
When a Printer supports this Delivery Method, it holds each Event When a Printer supports this Delivery Method, it holds each Event
Notification for an amount of time, called the Event Notification Lease Notification for an amount of time, called the Event Notification Lease
Time. Time.
When a Notification Recipient wants to receive Event Notifications, it When a Notification Recipient wants to receive Event Notifications, it
performs an IPP operation called 'Get-Notifications', which this performs an IPP operation called 'Get-Notifications', which this
document defines. This operation causes the Printer to return all Event document defines. This operation causes the Printer to return all Event
Notifications held for the Notification Recipient. If the Notification Notifications held for the Notification Recipient. If the Notification
Recipient has selected the option to wait for additional Event Recipient has selected the option to wait for additional Event
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Internet Printing Protocol/1.1: Implementer's Guide [ipp-iig] Internet Printing Protocol/1.1: Implementer's Guide [ipp-iig]
Mapping between LPD and IPP Protocols [RFC2569] Mapping between LPD and IPP Protocols [RFC2569]
Internet Printing Protocol/1.0 & 1.1: IPP Event Notification Internet Printing Protocol/1.0 & 1.1: IPP Event Notification
Specification [ipp-ntfy] Specification [ipp-ntfy]
The "Design Goals for an Internet Printing Protocol" document takes a The "Design Goals for an Internet Printing Protocol" document takes a
broad look at distributed printing functionality, and it enumerates broad look at distributed printing functionality, and it enumerates
real-life scenarios that help to clarify the features that need to be real-life scenarios that help to clarify the features that need to be
included in a printing protocol for the Internet. It identifies included in a printing protocol for the Internet. It identifies
requirements for three types of users: end users, operators, and requirements for three types of users: end users, operators, and
administrators. It calls out a subset of end user requirements that are administrators. It calls out a subset of end user requirements that
satisfied in IPP/1.0. A few OPTIONAL operator operations have been are satisfied in IPP/1.0. A few OPTIONAL operator operations have been
added to IPP/1.1. added to IPP/1.1.
The "Rationale for the Structure and Model and Protocol for the Internet The "Rationale for the Structure and Model and Protocol for the
Printing Protocol" document describes IPP from a high level view, Internet Printing Protocol" document describes IPP from a high level
defines a roadmap for the various documents that form the suite of IPP view, defines a roadmap for the various documents that form the suite
specification documents, and gives background and rationale for the IETF of IPP specification documents, and gives background and rationale for
working group's major decisions. the IETF working group's major decisions.
The "Internet Printing Protocol/1.1: Model and Semantics" document The "Internet Printing Protocol/1.1: Model and Semantics" document
describes a simplified model with abstract objects, their attributes, describes a simplified model with abstract objects, their attributes,
and their operations that are independent of encoding and transport. It and their operations that are independent of encoding and transport.
introduces a Printer and a Job object. The Job object optionally It introduces a Printer and a Job object. The Job object optionally
supports multiple documents per Job. It also addresses security, supports multiple documents per Job. It also addresses security,
internationalization, and directory issues. internationalization, and directory issues.
The "Internet Printing Protocol/1.1: Encoding and Transport" document is The "Internet Printing Protocol/1.1: Encoding and Transport" document
a formal mapping of the abstract operations and attributes defined in is a formal mapping of the abstract operations and attributes defined
the model document onto HTTP/1.1 [RFC2616]. It defines the encoding 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 rules for a new Internet MIME media type called "application/ipp".
document also defines the rules for transporting over HTTP a message This document also defines the rules for transporting over HTTP a
body whose Content-Type is "application/ipp". This document defines a message body whose Content-Type is "application/ipp". This document
new scheme named 'ippget' for identifying IPP printers and jobs. defines a new scheme named 'ippget' for identifying IPP printers and
jobs.
The "Internet Printing Protocol/1.1: Implementer's Guide" document gives The "Internet Printing Protocol/1.1: Implementer's Guide" document
insight and advice to implementers of IPP clients and IPP objects. It gives insight and advice to implementers of IPP clients and IPP
is intended to help them understand IPP/1.1 and some of the objects. It is intended to help them understand IPP/1.1 and some of
considerations that may assist them in the design of their client and/or the considerations that may assist them in the design of their client
IPP object implementations. For example, a typical order of processing and/or IPP object implementations. For example, a typical order of
requests is given, including error checking. Motivation for some of the processing requests is given, including error checking. Motivation for
specification decisions is also included. some of the specification decisions is also included.
The "Mapping between LPD and IPP Protocols" document gives some advice The "Mapping between LPD and IPP Protocols" document gives some advice
to implementers of gateways between IPP and LPD (Line Printer Daemon) to implementers of gateways between IPP and LPD (Line Printer Daemon)
implementations. implementations.
The "Event Notification Specification" document describes an extension The "Event Notification Specification" document describes an extension
to the IPP/1.0, IPP/1.1, and future versions. This extension allows a to the IPP/1.0, IPP/1.1, and future versions. This extension allows a
client to subscribe to printing related Events. Subscriptions are client to subscribe to printing related Events. Subscriptions are
modeled as Subscription Objects. The Subscription Object specifies that modeled as Subscription Objects. The Subscription Object specifies
when one of the specified Event occurs, the Printer sends an that when one of the specified Event occurs, the Printer sends an
asynchronous Event Notification to the specified Notification Recipient asynchronous Event Notification to the specified Notification Recipient
via the specified Delivery Method (i.e., protocol). A client associates via the specified Delivery Method (i.e., protocol). A client
Subscription Objects with a particular Job by performing the Create-Job- associates Subscription Objects with a particular Job by performing the
Subscriptions operation or by submitting a Job with subscription Create-Job-Subscriptions operation or by submitting a Job with
information. A client associates Subscription Objects with the Printer subscription information. A client associates Subscription Objects
by performing a Create-Printer-Subscriptions operation. Four other with the Printer by performing a Create-Printer-Subscriptions
operations are defined for Subscription Objects: Get-Subscriptions- operation. Four other operations are defined for Subscription Objects:
Attributes, Get-Subscriptions, Renew-Subscription, and Cancel- Get-Subscriptions-Attributes, Get-Subscriptions, Renew-Subscription,
Subscription. and Cancel-Subscription.
Table of Contents Table of Contents
1 Introduction ......................................................6 1 Introduction......................................................7
2 Terminology .......................................................6 2 Terminology.......................................................7
3 Model and Operation ...............................................7 3 Model and Operation...............................................8
4 General Information ...............................................8 4 General Information...............................................9
5 Get-Notifications operation ......................................10 5 Get-Notifications operation......................................11
5.1 Get-Notifications Request.......................................11 5.1 Get-Notifications Request.....................................12
5.2 Get-Notifications Response......................................12 5.2 Get-Notifications Response....................................13
6 Additional Printer Description Attributes ........................19 6 Subscription Template Attributes.................................18
6.1 begin-to-expire-time-interval" (integer(0:MAX)).................19 6.1 Subscription Template Attribute Conformance...................18
6.2 Additional Information about Subscription Template Attributes.18
6.2.1 notify-recipient-uri (uri).................................18
6.3 Subscription Description Attribute Conformance................19
7 New Status Codes .................................................19 7 Additional Printer Description Attributes........................19
7.1 redirection-other-site (0x300)..................................20 7.1 Printer Description Attribute Conformance.....................19
7.2 New Values for Existing Printer Description Attributes........19
7.2.1 notify-schemes-supported (1setOf uriScheme)................19
7.2.2 operations-supported (1setOf type2 enum)...................19
7.3 begin-to-expire-time-interval (integer(0:MAX))................20
8 Encoding .........................................................20 8 New Status Codes.................................................20
8.1 redirection-other-site (0x300)................................20
9 Conformance Requirements .........................................20 9 Encoding.........................................................20
10 IANA Considerations ..............................................21 10 Conformance Requirements.........................................21
11 Internationalization Considerations ..............................21 11 IANA Considerations..............................................21
12 Security Considerations ..........................................21 12 Internationalization Considerations..............................21
13 References .......................................................21 13 Security Considerations..........................................21
14 Authors' Addresses ...............................................22 14 References.......................................................22
15 Full Copyright Statement .........................................23 15 Authors' Addresses...............................................22
16 Full Copyright Statement.........................................23
Table of Tables
Table 1 - Information about the Delivery Method.......................9
Table 2 - Attributes in Event Notification Content...................16
Table 3 - Additional Attributes in Event Notification Content for Job
Events...........................................................17
Table 4 - Combinations of Events and Subscribed Events for "job-
impressions-completed"...........................................17
Table 5 - Additional Attributes in Event Notification Content for
Printer Events...................................................18
Table 6 - Operation-id assignments...................................19
1 Introduction 1 Introduction
The notification extension document [ipp-ntfy] defines operations that a The notification extension document [ipp-ntfy] defines operations that
client can perform in order to create Subscription Objects in a Printer a client can perform in order to create Subscription Objects in a
and carry out other operations on them. A Subscription Object represents Printer and carry out other operations on them. A Subscription Object
a Subscription abstraction. The Subscription Object specifies that when represents a Subscription abstraction. The Subscription Object
one of the specified Events occurs, the Printer sends an asynchronous specifies that when one of the specified Events occurs, the Printer
Event Notification to the specified Notification Recipient via the sends an asynchronous Event Notification to the specified Notification
specified Delivery Method (i.e., protocol). Recipient via the specified Delivery Method (i.e., protocol).
The notification extension document [ipp-ntfy] specifies that each The notification extension document [ipp-ntfy] specifies that each
Delivery Method is defined in another document. This document is one Delivery Method is defined in another document. This document is one
such document, and it specifies the 'ippget' delivery method. such document, and it specifies the 'ippget' delivery method.
The 'ippget' Delivery Method is a 'pull and push' Delivery Method. That The 'ippget' Delivery Method is a 'pull and push' Delivery Method. That
is, the Printer saves Event Notification for a period of time and is, the Printer saves Event Notification for a period of time and
expects the Notification Recipient to fetch the Event Notifications (the expects the Notification Recipient to fetch the Event Notifications
pull part). The Printer continues to send Event Notifications to the (the pull part). The Printer continues to send Event Notifications to
Notification Recipient as Events occur (the push part) if the client has the Notification Recipient as Events occur (the push part) if the
selected the option to wait for additional Event Notifications. client has selected the option to wait for additional Event
Notifications.
When a Printer supports this Delivery Method, it holds each Event When a Printer supports this Delivery Method, it holds each Event
Notification for an amount of time, called the Event Notification Lease Notification for an amount of time, called the Event Notification Lease
Time. Time.
When a Notification Recipient wants to receive Event Notifications, it When a Notification Recipient wants to receive Event Notifications, it
performs an IPP operation called 'Get-Notifications', which this performs an IPP operation called 'Get-Notifications', which this
document defines. This operation causes the Printer to return all Event document defines. This operation causes the Printer to return all Event
Notifications held for the Notification Recipient. If the Notification Notifications held for the Notification Recipient. If the Notification
Recipient has selected the option to wait for additional Event Recipient has selected the option to wait for additional Event
Notifications, the Printer the Printer continues to send Event Notifications, the Printer the Printer continues to send Event
Notifications to the Notification Recipient as Events occur. Notifications to the Notification Recipient as Events occur.
2 Terminology 2 Terminology
This section defines the following terms that are used throughout this This section defines the following terms that are used throughout this
document: document:
Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD
MAY, NEED NOT, and OPTIONAL, have special meaning relating to NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to
conformance to this specification. These terms are defined in [RFC2911 conformance to this specification. These terms are defined in [RFC2911
section 13.1 on conformance terminology, most of which is taken from
section 13.1 on conformance terminology, most of which is taken from RFC RFC 2119 [RFC2119].
2119 [RFC2119].
Event Notification Lease: The lease that is associated with an Event Event Notification Lease: The lease that is associated with an Event
Notification. When the lease expires, the Printer discards the Notification. When the lease expires, the Printer discards the
associated Event Notification. associated Event Notification.
Event Notification Lease Time: The expiration time assigned to a lease Event Notification Lease Time: The expiration time assigned to a lease
that is associated with an Event Notification. that is associated with an Event Notification.
Event Notification Attributes Group: The attributes group in a response Event Notification Attributes Group: The attributes group in a response
that contains attributes that are part of an Event Notification. that contains attributes that are part of an Event Notification.
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When an Event occurs, the Printer MUST generate an Event Notification When an Event occurs, the Printer MUST generate an Event Notification
and MUST assign it the Event Notification Lease Time. The Printer MUST and MUST assign it the Event Notification Lease Time. The Printer MUST
hold an Event Notification for its assigned Event Notification Lease hold an Event Notification for its assigned Event Notification Lease
Time. The Printer MUST assign the same Event Notification Lease Time to Time. The Printer MUST assign the same Event Notification Lease Time to
each Event Notification. each Event Notification.
When a Notification Recipient wants to receive Event Notifications, it When a Notification Recipient wants to receive Event Notifications, it
performs the Get-Notifications operation, which causes the Printer to performs the Get-Notifications operation, which causes the Printer to
return all unexpired Event Notifications held for the Notification return all unexpired Event Notifications held for the Notification
Recipient. If the Notification Recipient has selected the option to wait Recipient. If the Notification Recipient has selected the option to
for additional Event Notifications, the response to the Get- wait for additional Event Notifications, the response to the Get-
Notifications request continues indefinitely as the Printer continues to Notifications request continues indefinitely as the Printer continues
send Event Notifications in the response as Events occur. For the Get- to send Event Notifications in the response as Events occur. For the
Notification operation, the Printer sends only those Event Notifications Get-Notification operation, the Printer sends only those Event
that are generated from Subscription Objects whose "notify-recipient- Notifications that are generated from Subscription Objects whose
"notify-recipient-uri" equals the "notify-recipient-uri" Operation
uri" equals the "notify-recipient-uri" Operation Attribute in the Get- Attribute in the Get-Notifications operation.
Notifications operation.
If a Notification Recipient performs the Get-Notifications operation If a Notification Recipient performs the Get-Notifications operation
twice in quick succession, it will receive nearly the same Event twice in quick succession, it will receive nearly the same Event
Notification both times because most of the Event Notifications are Notification both times because most of the Event Notifications are
those that the Printer saves for a few seconds after the Event occurs. those that the Printer saves for a few seconds after the Event occurs.
There are two possible differences. Some old Event Notifications may not There are two possible differences. Some old Event Notifications may
be present in the second response because their Event Notification not be present in the second response because their Event Notification
Leases have expired. Some new Event Notifications may be present in the Leases have expired. Some new Event Notifications may be present in
second response but not the first response. the second response but not the first response.
When the Notification Recipient requests Event Notifications for per-Job When the Notification Recipient requests Event Notifications for per-
Subscription Objects, the Notification Recipient typically performs the Job Subscription Objects, the Notification Recipient typically performs
Get-Notifications operation within a second of performing the the Get-Notifications operation within a second of performing the
Subscription Creation operation. Because the Printer is likely to save Subscription Creation operation. Because the Printer is likely to save
Event Notifications for several seconds, the Notification Recipient is Event Notifications for several seconds, the Notification Recipient is
unlikely to miss any Event Notifications that occur between the unlikely to miss any Event Notifications that occur between the
Subscription Creation and the Get-Notifications operation. Subscription Creation and the Get-Notifications operation.
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.
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sends in an Event Notification sends in an Event Notification
content and the conformance content and the conformance
requirements thereof? requirements thereof?
12. What are the additional None 12. What are the additional None
Subscription Template and/or Subscription Template and/or
Subscription Description Subscription Description
attributes and the conformance attributes and the conformance
requirements thereof? requirements thereof?
13. What are the additional 13. What are the additional None
Printer Description attributes Printer Description attributes
and the conformance None and the conformance
requirements thereof? requirements thereof?
5 Get-Notifications operation 5 Get-Notifications operation
This operation causes the Printer to return all Event Notifications held This operation causes the Printer to return all Event Notifications
for the Notification Recipient. held for the Notification Recipient.
A Printer MUST support this operation. A Printer MUST support this operation.
When a Printer performs this operation, it MUST return all and only When a Printer performs this operation, it MUST return all and only
those Event Notifications: those Event Notifications:
a)Whose associated Subscription Object's "notify-recipient-uri" a)Whose associated Subscription Object's "notify-recipient-uri"
attribute equals the "notify-recipient-uri" Operation attribute attribute equals the "notify-recipient-uri" Operation attribute
AND AND
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The Printer MUST accept the request in any state (see [RFC2911] The Printer MUST accept the request in any state (see [RFC2911]
"printer-state" and "printer-state-reasons" attributes) and MUST remain "printer-state" and "printer-state-reasons" attributes) and MUST remain
in the same state with the same "printer-state-reasons". in the same state with the same "printer-state-reasons".
Access Rights: If the policy of the Printer is to allow all users to Access Rights: If the policy of the Printer is to allow all users to
access all Event Notifications, then the Printer MUST accept this access all Event Notifications, then the Printer MUST accept this
operation from any user. Otherwise, the authenticated user (see operation from any user. Otherwise, the authenticated user (see
[RFC2911] section 8.3) performing this operation MUST either be the [RFC2911] section 8.3) performing this operation MUST either be the
owner of each Subscription Object identified by the "notify-recipient- owner of each Subscription Object identified by the "notify-recipient-
uri" Operation attribute (as determined during a Subscription Creation uri" Operation attribute (as determined during a Subscription Creation
Operation) or an operator or administrator of the Printer (see [RFC2911] Operation) or an operator or administrator of the Printer (see
Sections 1 and 8.5). Otherwise, the IPP object MUST reject the [RFC2911] Sections 1 and 8.5). Otherwise, the IPP object MUST reject
operation and return: 'client-error-forbidden', 'client-error-not- the operation and return: 'client-error-forbidden', 'client-error-not-
authenticated', or 'client-error-not-authorized' as appropriate. authenticated', or 'client-error-not-authorized' as appropriate.
5.1 Get-Notifications Request 5.1 Get-Notifications Request
The following groups of attributes are part of the Get-Notifications The following groups of attributes are part of the Get-Notifications
Request: Request:
Group 1: Operation Attributes Group 1: Operation Attributes
Natural Language and Character Set: Natural Language and Character Set:
The "attributes-charset" and "attributes-natural-language" The "attributes-charset" and "attributes-natural-language"
attributes as described in [RFC2911] section 3.1.4.1. attributes as described in [RFC2911] section 3.1.4.1.
Target: Target:
The "printer-uri" (uri) operation attribute which is the target for The "printer-uri" (uri) operation attribute which is the target
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 supplied The "requesting-user-name" (name(MAX)) attribute SHOULD be
by the client as described in [RFC2911] section 8.3. supplied by the client as described in [RFC2911] section 8.3.
"notify-recipient-uri" (url): "notify-recipient-uri" (url):
The client MUST supply this attribute. The Printer object MUST The client MUST supply this attribute. The Printer object MUST
support this attribute. The Printer matches the value of this support this attribute. The Printer matches the value of this
attribute (byte for byte with no case conversion) against the value attribute (byte for byte with no case conversion) against the
of the "notify-recipient-uri" in each Subscription Object in the value of the "notify-recipient-uri" in each Subscription Object in
Printer. If there are no matches, the IPP Printer MUST return the the Printer. If there are no matches, the IPP Printer MUST return
'client-error-not-found' status code. For each matched the 'client-error-not-found' status code. For each matched
Subscription Object, the IPP Printer MUST return all unexpired Subscription Object, the IPP Printer MUST return all unexpired
Event Notifications associated with it. The Printer MUST send Event Notifications associated with it. The Printer MUST send
additional Event Notifications as Events occur if and only if the additional Event Notifications as Events occur if and only if the
value of the "notify-no-wait" attribute is 'false' or not supplied value of the "notify-no-wait" attribute is 'false' or not supplied
by the client (see the next attribute below). by the client (see the next attribute below).
Note: this attribute allows a subscribing client to pick URLs that Note: this attribute allows a subscribing client to pick URLs that
are unique, e.g. the client's own URL or a friend's URL, which in are unique, e.g. the client's own URL or a friend's URL, which in
both cases is likely the URL of the person's host. An application both cases is likely the URL of the person's host. An application
could make a URL unique for each application. could make a URL unique for each application.
"notify-no-wait" (boolean): "notify-no-wait" (boolean):
The client MAY supply this attribute. The Printer object MUST The client MAY supply this attribute. The Printer object MUST
support this attribute. If the value of this attribute is 'false', support this attribute. If the value of this attribute is 'false',
the Printer MUST send all un-expired Event Notifications (as the Printer MUST send all un-expired Event Notifications (as
defined in the previous attribute) and it MUST continue to send defined in the previous attribute) and it MUST continue to send
responses for as long as the Subscription Objects associated with responses for as long as the Subscription Objects associated with
the specified "notify-recipient-uri" continue to exist. If the the specified "notify-recipient-uri" continue to exist. If the
value of this attribute is 'true', the Printer MUST send all un- value of this attribute is 'true', the Printer MUST send all un-
expired Event Notifications (as defined in the previous attribute) expired Event Notifications (as defined in the previous attribute)
and the Printer MUST conclude the operation without waiting for any and the Printer MUST conclude the operation without waiting for
additional Events to occur. If the client doesn't supply this any additional Events to occur. If the client doesn't supply this
attribute, the Printer MUST behave as if the client had supplied attribute, the Printer MUST behave as if the client had supplied
this attribute with the value of 'false'. this attribute with the value of 'false'.
5.2 Get-Notifications Response 5.2 Get-Notifications Response
The following groups of attributes are part of the Get-Notifications The following groups of attributes are part of the Get-Notifications
Response: Response:
Group 1: Operation Attributes Group 1: Operation Attributes
Status Message: Status Message:
In addition to the REQUIRED status code returned in every response, In addition to the REQUIRED status code returned in every
the response OPTIONALLY includes a "status-message" (text(255)) response, the response OPTIONALLY includes a "status-message"
and/or a "detailed-status-message" (text(MAX)) operation attribute (text(255)) and/or a "detailed-status-message" (text(MAX))
as described in [RFC2911] sections 13 and 3.1.6. operation attribute as described in [RFC2911] sections 13 and
3.1.6.
The Printer can return any status codes defined in [RFC2911]. If The Printer can return any status codes defined in [RFC2911]. If
the status code is not 'successful-', the Printer MUST NOT return the status code is not 'successful-', the Printer MUST NOT return
any Event Notification Attribute groups. The following is a any Event Notification Attribute groups. The following is a
description of the important status codes: description of the important status codes:
successful-ok: the response contains all Event Notification successful-ok: the response contains all Event Notification
associated with the specified "notify-recipient-uri". If the associated with the specified "notify-recipient-uri". If the
specified Subscription Objects have no associated Event specified Subscription Objects have no associated Event
Notification, the response MUST contain zero Event Notification, the response MUST contain zero Event
Notifications. Notifications.
client-error-not-found: The Printer has no Subscription Object's client-error-not-found: The Printer has no Subscription
whose "notify-recipient-uri" attribute equals the "notify- Object's whose "notify-recipient-uri" attribute equals the
recipient-uri" Operation attribute. "notify-recipient-uri" Operation attribute.
server-error-busy: The Printer is too busy to accept this server-error-busy: The Printer is too busy to accept this
operation. If the "suggested-ask-again-time-interval" operation. If the "suggested-ask-again-time-interval"
operation attribute is present in the Operation Attributes of operation attribute is present in the Operation Attributes of
the response, then the Notification Recipient SHOULD wait for the response, then the Notification Recipient SHOULD wait for
the number of seconds specified by the "suggested-ask-again- the number of seconds specified by the "suggested-ask-again-
time-interval" attribute before performing this operation time-interval" attribute before performing this operation
again. If the "suggested-ask-again-time-interval" Operation again. If the "suggested-ask-again-time-interval" Operation
Attribute is not present, the Notification Recipient should Attribute is not present, the Notification Recipient should
use the normal network back-off algorithms for determining use the normal network back-off algorithms for determining
when to perform this operation again. when to perform this operation again.
redirection-other-site: The Printer does not handle this redirection-other-site: The Printer does not handle this
operation and requests the Notification Recipient to perform operation and requests the Notification Recipient to perform
the operation with the uri specified by the "notify-ippget- the operation with the uri specified by the "notify-ippget-
redirect" Operation Attribute in the response.. redirect" Operation Attribute in the response.
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 "notify- The Printer MUST use the values of "notify-charset" and "notify-
natural-language", respectively, from one Subscription Object natural-language", respectively, from one Subscription Object
associated with the Event Notifications in this response. associated with the Event Notifications in this response.
Normally, there is only one matched Subscription Object, or the Normally, there is only one matched Subscription Object, or the
value of the "notify-charset" and "notify-natural-language" value of the "notify-charset" and "notify-natural-language"
attributes is the same in all Subscription Objects. If not, the attributes is the same in all Subscription Objects. If not, the
Printer MUST pick one Subscription Object from which to obtain the Printer MUST pick one Subscription Object from which to obtain the
value of these attributes. The algorithm for picking the value of these attributes. The algorithm for picking the
Subscription Object is implementation dependent. The choice of Subscription Object is implementation dependent. The choice of
natural language is not critical because 'text' and 'name' values natural language is not critical because 'text' and 'name' values
can override the "attributes-natural-language" Operation attribute. can override the "attributes-natural-language" Operation
The Printer's choice of charset is critical because a bad choice attribute. The Printer's choice of charset is critical because a
may leave it unable to send some 'text' and 'name' values bad choice may leave it unable to send some 'text' and 'name'
accurately. values accurately.
"printer-up-time" (integer(0:MAX)): "printer-up-time" (integer(0:MAX)):
The value of this attribute is the Printer's "printer-up-time" The value of this attribute is the Printer's "printer-up-time"
attribute at the time the Printer sends this response. Because each attribute at the time the Printer sends this response. Because
Event Notification also contains the value of this attribute when each Event Notification also contains the value of this attribute
the event occurred, the value of this attribute lets a Notification when the event occurred, the value of this attribute lets a
Recipient know when each Event Notification occurred relative to Notification Recipient know when each Event Notification occurred
the time of this response. relative to the time of this response.
"suggested-ask-again-time-interval" (integer(0:MAX)): "suggested-ask-again-time-interval" (integer(0:MAX)):
The value of this attribute is the number of seconds that the The value of this attribute is the number of seconds that the
Notification Recipient SHOULD wait before trying this operation Notification Recipient SHOULD wait before trying this operation
again when again when
a)the Printer returns the 'server-error-busy' status code OR a)the Printer returns the 'server-error-busy' status code OR
b)the Printer returns the 'successful-ok' status code and the b)the Printer returns the 'successful-ok' status code and
client supplied the "notify-no-wait" attribute with a value the client supplied the "notify-no-wait" attribute with a
of 'true'. value of 'true'.
This value is intended to help the client be a good network This value is intended to help the client be a good network
citizen. citizen.
"notify-ippget-redirect" (uri): "notify-ippget-redirect" (uri):
The value of this attribute is uri that the Notification Recipient The value of this attribute is uri that the Notification Recipient
MUST use for the Get-Notifications operation. This attribute is MUST use for the Get-Notifications operation. This attribute is
present in the Operation Attributes if and only if the status code present in the Operation Attributes if and only if the status code
has the value 'redirection-other-site'. has the value 'redirection-other-site'.
Group 2: Unsupported Attributes Group 2: Unsupported Attributes
See [RFC2911] section 3.1.7 for details on returning Unsupported See [RFC2911] section 3.1.7 for details on returning Unsupported
Attributes. Attributes.
If the "subscription-ids" attribute contained subscription-ids that If the "subscription-ids" attribute contained subscription-ids
do not exist, the Printer returns them in this group as value of that do not exist, the Printer returns them in this group as value
the "subscription-ids" attribute. of the "subscription-ids" attribute.
Group 3 through N: Event Notification Attributes Group 3 through N: Event Notification Attributes
The Printer responds with one Event Notification Attributes Group The Printer responds with one Event Notification Attributes Group
per matched Event Notification. The initial matched Event per matched Event Notification. The initial matched Event
Notifications are all un-expired Event Notification associated with Notifications are all un-expired Event Notification associated
the matched Subscription Objects. If the Notification Recipient has with the matched Subscription Objects. If the Notification
selected the option to wait for additional Event Notifications, the Recipient has selected the option to wait for additional Event
Printer the subsequent Event Notifications in the response are Notifications, the Printer the subsequent Event Notifications in
Event Notifications associated with the matched Subscription the response are Event Notifications associated with the matched
Objects as the corresponding Event occurs. Subscription Objects as the corresponding Event occurs.
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 initial burst of data, which includes the Operation Attributes
Group and one Event Notification Attributes Groups per Event Group and one Event Notification Attributes Groups per Event
Notification that the Printer is holding. After the initial burst Notification that the Printer is holding. After the initial burst
of data, if the Notification Recipient has selected the option to of data, if the Notification Recipient has selected the option to
wait for additional Event Notifications, the Notification Recipient wait for additional Event Notifications, the Notification
receives occasional Event Notification Attribute Groups. Proxy Recipient receives occasional Event Notification Attribute Groups.
servers may delay some Event Notifications or cause time-outs to Proxy servers may delay some Event Notifications or cause time-
occur. The client MUST be prepared to perform the Get-Notifications outs to occur. The client MUST be prepared to perform the Get-
operation again when time-outs occur. Notifications operation again when time-outs occur.
Each Event Notification Group MUST start with an 'event- Each Event Notification 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]). Additional Attribute Tags" in [ipp-ntfy]).
Each attribute is encoded using the IPP rules for encoding Each attribute is encoded using the IPP rules for encoding
attributes [RFC2910] and may be encoded in any order. Note: the attributes [RFC2910] and may be encoded in any order. Note: the
Get-Jobs response in [RFC2911] acts as a model for encoding Get-Jobs response in [RFC2911] acts as a model for encoding
multiple groups of attributes. multiple groups of attributes.
skipping to change at page 16, line 4 skipping to change at page 16, line 24
Table 2 - Attributes in Event Notification Content Table 2 - Attributes in Event Notification Content
Source Value Sends Source Object Source Value Sends Source Object
notify-subscription-id (integer(1:MAX)) MUST Subscription notify-subscription-id (integer(1:MAX)) MUST Subscription
notify-printer-uri (uri) MUST Subscription notify-printer-uri (uri) MUST Subscription
notify-subscribed-event (type2 keyword) MUST Event notify-subscribed-event (type2 keyword) MUST Event
Notification Notification
Source Value Sends Source Object
printer-up-time (integer(MIN:MAX)) MUST Printer printer-up-time (integer(MIN:MAX)) MUST Printer
printer-current-time (dateTime)* MUST Printer printer-current-time (dateTime)* MUST Printer
notify-sequence-number (integer (0:MAX)) MUST Subscription notify-sequence-number (integer (0:MAX)) MUST Subscription
notify-charset (charset) MUST Subscription notify-charset (charset) MUST Subscription
notify-natural-language (naturalLanguage) MUST Subscription notify-natural-language (naturalLanguage) MUST Subscription
skipping to change at page 17, line 4 skipping to change at page 16, line 48
Notification Notification
attributes from the "notify-attributes" MUST Printer attributes from the "notify-attributes" MUST Printer
attribute *** attribute ***
attributes from the "notify-attributes" MUST Job attributes from the "notify-attributes" MUST Job
attribute *** attribute ***
attributes from the "notify-attributes" MUST Subscription attributes from the "notify-attributes" MUST Subscription
attribute *** attribute ***
* The Printer MUST send "printer-current-time" if and only if it * The Printer MUST send "printer-current-time" if and only if it
supports the "printer-current-time" attribute on the Printer supports the "printer-current-time" attribute on the Printer
object. object.
** If the associated Subscription Object does not contain a ** If the associated Subscription Object does not contain a
"notify-user-data" attribute, the Printer MUST send an octet-string "notify-user-data" attribute, the Printer MUST send an octet-
of length 0. string of length 0.
*** If the "notify-attributes" attribute is present on the *** If the "notify-attributes" attribute is present on the
Subscription Object, the Printer MUST send all attributes specified Subscription Object, the Printer MUST send all attributes
by the "notify-attributes" attribute. Note: if the Printer doesn't specified by the "notify-attributes" attribute. Note: if the
support the "notify-attributes" attribute, it is not present on the Printer doesn't support the "notify-attributes" attribute, it is
associated Subscription Object. not present on the associated Subscription Object.
For Event Notifications for Job Events, the Printer includes the For Event Notifications for Job Events, the Printer includes the
following additional attributes. following additional attributes.
Table 3 - Additional Attributes in Event Notification Content for Table 3 - Additional Attributes in Event Notification Content for
Job Events Job Events
Source Value Sends Source Object Source Value Sends Source Object
job-id (integer(1:MAX)) MUST Job job-id (integer(1:MAX)) MUST Job
skipping to change at page 18, line 16 skipping to change at page 17, line 47
impressions-completed" impressions-completed"
Job Event Subscribed Job Event Job Event Subscribed Job Event
'job-progress' 'job-progress' 'job-progress' 'job-progress'
'job-completed' 'job-completed' 'job-completed' 'job-completed'
'job-completed' 'job-state-changed' 'job-completed' 'job-state-changed'
For Event Notification for Printer Events, the Printer includes the For Event Notification for Printer Events, the Printer includes
following additional attributes. the following additional attributes.
Table 5 - Additional Attributes in Event Notification Content for Table 5 - Additional Attributes in Event Notification Content for
Printer Events Printer Events
Source Value Sends Source Object Source Value Sends Source Object
printer-state (type1 enum) MUST Printer printer-state (type1 enum) MUST Printer
printer-state-reasons (1setOf type2 MUST Printer printer-state-reasons (1setOf type2 MUST Printer
keyword) keyword)
printer-is-accepting-jobs (boolean) MUST Printer printer-is-accepting-jobs (boolean) MUST Printer
6 Additional Printer Description Attributes 6 Subscription Template Attributes
6.1 begin-to-expire-time-interval" (integer(0:MAX)) This section defines the Subscription object conformance requirements
for Printers.
6.1 Subscription Template Attribute Conformance
The 'ippget' Delivery Method has the same conformance requirements for
Subscription Template attributes as defined in [ipp-ntfy]. The
'ippget' Delivery Method does not define any addition Subscription
Template attributes.
6.2 Additional Information about Subscription Template Attributes
This section defines additional information about Subscription Template
attributes defined in [ipp-ntfy].
6.2.1notify-recipient-uri (uri)
This section describes the syntax of the value of this attribute for
the 'ippget' Delivery Method. The syntax for values of this attribute
for other Delivery Method is defined in other Delivery Method
Documents.
In order to support the 'ippget' Delivery Method and Protocol, the
Printer MUST support the following syntax:
The 'ippget://' URI scheme. The remainder of the URI indicates
something unique about the Notification Recipient, such as its host
and address that the Printer uses to match the "notify-recipient-
uri" Operation attribute supplied in the Get-Notifications request.
6.3 Subscription Description Attribute Conformance
The 'ippget' Delivery Method has the same conformance requirements for
Subscription Description attributes as defined in [ipp-ntfy]. The
'ippget' Delivery Method does not define any addition Subscription
Description attributes.
7 Additional Printer Description Attributes
This section defines the Printer Description Attributes conformance
requirements for Printers.
7.1 Printer Description Attribute Conformance
The 'ippget' Delivery Method has the same conformance requirements for
Printer Description attributes as defined in [ipp-ntfy]. The 'ippget'
Delivery Method does not define any addition Printer Description
attributes.
7.2 New Values for Existing Printer Description Attributes
This section defines additional values for existing Printer Description
attributes.
7.2.1notify-schemes-supported (1setOf uriScheme)
The following "notify-schemes-supported" value is added in order to
support the new Delivery Method defined in this document:
'ippget' - The IPP Notification Delivery Method defined in this
document.
7.2.2operations-supported (1setOf type2 enum)
Table 6 lists the "operation-id" value added in order to support the
new operation defined in this document.
Table 6 - Operation-id assignments
Value Operation Name
0x001C Get-Notifications
7.3 begin-to-expire-time-interval (integer(0:MAX))
This attribute specifies the number of seconds that a Printer keeps an This attribute specifies the number of seconds that a Printer keeps an
Event Notification that is associated with this Delivery Method. Event Notification that is associated with this Delivery Method.
The Printer MUST support this attribute if it supports this Delivery The Printer MUST support this attribute if it supports this Delivery
Method. Method.
The value of this attribute is the minimum number of seconds that MUST The value of this attribute is the minimum number of seconds that MUST
elapse between the time the Printer creates an Event Notification object elapse between the time the Printer creates an Event Notification
for this Delivery Method and the time the Printer discards the same object for this Delivery Method and the time the Printer discards the
Event Notification. same Event Notification.
For example, assume the following: For example, assume the following:
1. a client performs a Job Creation operation that creates a 1. a client performs a Job Creation operation that creates a
Subscription Object associated with this Delivery Method, AND Subscription Object associated with this Delivery Method, AND
2. an Event associated with the new Job occurs immediately after the 2. an Event associated with the new Job occurs immediately after the
Subscription Object is created, AND Subscription Object is created, AND
3. the same client or some other client performs a Get-Notifications 3. the same client or some other client performs a Get-Notifications
operation N seconds after the Job Creation operation. operation N seconds after the Job Creation operation.
Then, if N is less than the value of this attribute, the client Then, if N is less than the value of this attribute, the client
performing the Get-Notifications operations can expect not miss any performing the Get-Notifications operations can expect not miss any
Event-Notifications, barring some unforeseen lack of memory space in the Event-Notifications, barring some unforeseen lack of memory space in
Printer. the Printer.
7 New Status Codes 8 New Status Codes
The following status codes are defined as extensions for this Delivery The following status codes are defined as extensions for this Delivery
Method and are returned as the status code of the Get-Notifications Method and are returned as the status code of the Get-Notifications
operation. operation.
7.1 redirection-other-site (0x300) 8.1 redirection-other-site (0x300)
This status code means that the Printer doesn't perform that Get- This status code means that the Printer doesn't perform that Get-
Notifications operation and that the "notify-ippget-redirect" Operation Notifications operation and that the "notify-ippget-redirect" Operation
Attribute in the response contains the uri that the Notification Attribute in the response contains the uri that the Notification
Recipient MUST use for performing the Get-Notifications operation. Recipient MUST use for performing the Get-Notifications operation.
8 Encoding 9 Encoding
The operation-id assigned for the Get-Notifications operation is:
0x001C
and should be added to the next version of [RFC2911] section 4.4.15
"operations-supported".
This notification delivery method uses the IPP transport and encoding This notification delivery method uses the IPP transport and encoding
[RFC2910] for the Get-Notifications operation with one extension: [RFC2910] for the Get-Notifications operation with one extension:
notification-attributes-tag = %x07 ; tag of notification-attributes-tag = %x07 ; tag of
7 7
9 Conformance Requirements 10 Conformance Requirements
If the Printer supports the 'ippget' Delivery Method, the Printer MUST: If the Printer supports the 'ippget' Delivery Method, the Printer MUST:
1.meet the conformance requirements defined in [ipp-ntfy]. 1.meet the conformance requirements defined in [ipp-ntfy].
2.support the Get-Notifications operation defined in section 5. 2.support the Get-Notifications operation defined in section 5.
3.support the "begin-to-expire-time-interval" attribute defined in 3.support the Subscription object attributes as defined in section 6.
section 6.1.
4.support the "redirection-other-site" status code defined 7.1 4.support the additional values for IPP/1.1 Printer Description
attributes defined in section 7.2.
10 IANA Considerations 5.support the "begin-to-expire-time-interval" Printer Description
attribute defined in section 7.3.
There is nothing to register. 6.support the "redirection-other-site" status code defined 8.1
11 Internationalization Considerations 11 IANA Considerations
The 'ippget' URL scheme for the 'ippget' Delivery Method will be
registered with IANA according to the procedures of [RFC2717].
12 Internationalization Considerations
The IPP Printer MUST localize the "notify-text" attribute as specified The IPP Printer MUST localize the "notify-text" attribute as specified
in section 14 of [ipp-ntfy]. in section 14 of [ipp-ntfy].
In addition, when the client receives the Get-Notifications response, it In addition, when the client receives the Get-Notifications response,
is expected to localize the attributes that have the 'keyword' attribute it is expected to localize the attributes that have the 'keyword'
syntax according to the charset and natural language requested in the attribute syntax according to the charset and natural language
Get-Notifications request. requested in the Get-Notifications request.
12 Security Considerations 13 Security Considerations
The IPP Model and Semantics document [RFC2911] discusses high-level The IPP Model and Semantics document [RFC2911] discusses high-level
security requirements (Client Authentication, Server Authentication and security requirements (Client Authentication, Server Authentication and
Operation Privacy). Client Authentication is the mechanism by which the Operation Privacy). Client Authentication is the mechanism by which
client proves its identity to the server in a secure manner. Server the client proves its identity to the server in a secure manner.
Authentication is the mechanism by which the server proves its identity Server Authentication is the mechanism by which the server proves its
to the client in a secure manner. Operation Privacy is defined as a identity to the client in a secure manner. Operation Privacy is
mechanism for protecting operations from eavesdropping. defined as a mechanism for protecting operations from eavesdropping.
Unlike other Event Notification delivery methods in which the IPP Unlike other Event Notification delivery methods in which the IPP
Printer initiates the Event Notification, with the method defined in Printer initiates the Event Notification, with the method defined in
this document, the Notification Recipient is the client who s the Get- this document, the Notification Recipient is the client who s the
Notifications operation. Therefore, there is no chance of "spam" Get-Notifications operation. Therefore, there is no chance of "spam"
notifications with this method. Furthermore, such a client can close notifications with this method. Furthermore, such a client can close
down the HTTP channel at any time, and so can avoid future unwanted down the HTTP channel at any time, and so can avoid future unwanted
Event Notifications at any time. Event Notifications at any time.
13 References 14 References
[ipp-ntfy] [ipp-ntfy]
R. Herriot, Hastings, T., Isaacson, S., Martin, J., deBry, R., R. Herriot, Hastings, T., Isaacson, S., Martin, J., deBry, R.,
Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP
Event Notification Specification", <draft-ietf-ipp-not-spec- Event Notification Specification", <draft-ietf-ipp-not-spec-
04.txt>, June 30, 2000. 04.txt>, June 30, 2000.
[rfc2026] [rfc2026]
S. Bradner, "The Internet Standards Process -- Revision 3", RFC S. Bradner, "The Internet Standards Process -- Revision 3", RFC
2026, October 1996. 2026, October 1996.
skipping to change at page 22, line 23 skipping to change at page 22, line 39
[RFC2910] [RFC2910]
Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
Protocol/1.1: Encoding and Transport", RFC 2910, September 2000. Protocol/1.1: Encoding and Transport", RFC 2910, September 2000.
[RFC2911] [RFC2911]
R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell, R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell,
"Internet Printing Protocol/1.1: Model and Semantics", RFC 2911, "Internet Printing Protocol/1.1: Model and Semantics", RFC 2911,
September 2000. September 2000.
14 Authors' Addresses 15 Authors' Addresses
Robert Herriot Robert Herriot
Xerox Corp. Xerox Corp.
3400 Hill View Ave, Building 1 3400 Hill View Ave, Building 1
Palo Alto, CA 94304 Palo Alto, CA 94304
Phone: 650-813-7696 Phone: 650-813-7696
Fax: 650-813-6860 Fax: 650-813-6860
e-mail: robert.herriot@pahv.xerox.com e-mail: robert.herriot@pahv.xerox.com
skipping to change at page 23, line 5 skipping to change at page 23, line 21
Harry Lewis Harry Lewis
IBM IBM
P.O. Box 1900 P.O. Box 1900
Boulder, CO 80301-9191 Boulder, CO 80301-9191
Phone: 303-924-5337 Phone: 303-924-5337
FAX: FAX:
e-mail: harryl@us.ibm.com e-mail: harryl@us.ibm.com
15 Full Copyright Statement 16 Full Copyright Statement
Copyright (C) The Internet Society (2000). All Rights Reserved. Copyright (C) The Internet Society (2000). All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or others, and derivative works that comment on or otherwise explain it or
assist in its implementation may be prepared, copied, published and assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind, distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included provided that the above copyright notice and this paragraph are
on all such copies and derivative works. However, this document itself included on all such copies and derivative works. However, this
may not be modified in any way, such as by removing the copyright notice document itself may not be modified in any way, such as by removing the
or references to the Internet Society or other Internet organizations, copyright notice or references to the Internet Society or other
except as needed for the purpose of developing Internet standards in Internet organizations, except as needed for the purpose of developing
which case the procedures for copyrights defined in the Internet Internet standards in which case the procedures for copyrights defined
Standards process must be followed, or as required to translate it into in the Internet Standards process must be followed, or as required to
languages other than English. translate it into languages other than English.
The limited permissions granted above are perpetual and will not be The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an "AS This document and the information contained herein is provided on an
IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT
LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL
INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE. FITNESS FOR A PARTICULAR PURPOSE.
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