Internet Printing Protocol WG Robert Herriot

Internet Printing Protocol WG Robert Herriot
INTERNET-DRAFT Tom Hastings
<draft-ietf-ipp-notify-mailto-04.txt> Carl-Uno Manros
Updates: RFC 2911 Xerox Corp.
[Target Category: standards track] Henrik Holst
Expires: January 17, 2002 i-data international a/s
July 17, 2001

Internet Printing Protocol (IPP):
The 'mailto' Delivery Method for Event Notifications

Copyright (C) The Internet Society (2000). All Rights Reserved.
Status of this Memo

This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of [RFC2026]. Internet-Drafts are
working documents of the Internet Engineering Task Force (IETF), its
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Internet-Drafts are draft documents valid for a maximum of six months
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Abstract

This document describes an extension to the Internet Printing
Protocol/1.0 (IPP) [RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910].
This document specifies the 'mailto' Delivery Method for use with the
"IPP Event Notifications and Subscriptions" specification [ipp-ntfy].
When IPP Notification [ipp-ntfy] is supported, the Delivery Method
defined in this document is one of the RECOMMENDED Delivery Methods
for Printers to support.

For this Delivery Method, when an Event occurs, the Printer
immediately sends an Event Notification via an email message to the
Notification Recipient specified in the Subscription Object. The
message body of the email consists of Human Consumable text that is
not intended to be parsed by a machine. The Notification Recipient
receives the Event Notification in the same way as it receives any
other email message.

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Table of Contents

1 Introduction.....................................................4

2 Terminology......................................................4

3 Model and Operation..............................................5

4 General Information..............................................6

5 Subscription Template Attributes.................................8
5.1 Additional Subscription Template Attributes....................8
5.1.1 notify-mailto-text-only (boolean)............................8
5.2 Additional Information about Subscription Template Attributes..9
5.2.1 notify-recipient-uri (uri)...................................9
5.2.2 notify-user-data (octetString(63))..........................10

6 Event Notification Content......................................10
6.1 Headers.......................................................11
6.1.1 'Date' header...............................................11
6.1.2 'From' header...............................................11
6.1.3 'Subject' header............................................12
6.1.4 'Sender' header.............................................12
6.1.5 'Reply-to' header...........................................13
6.1.6 'To' header.................................................13
6.1.7 'Content-type' header.......................................13
6.2 Message Body..................................................14
6.3 Plain Text Content............................................14
6.3.1 Event Notification Content Common to All Events.............15
6.3.2 Additional Event Notification Content for Job Events........17
6.3.3 Additional Event Notification Content for Printer Events....18
6.4 Examples......................................................18
6.4.1 Job Event Example...........................................19
6.4.2 Printer Event Example.......................................20
6.4.3 Printer Event Example (localized to Danish)................21

7 Conformance Requirements........................................23

8 IANA Considerations.............................................23
8.1 Attribute Registration........................................23
8.2 Additional uriScheme Attribute Value Registration for the
"operations-supported" Printer Attribute..........................24

9 Internationalization Considerations.............................24

10 Security Considerations........................................24

11 References.....................................................25

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12 Author's Addresses.............................................27

13 Summary of Base IPP Documents..................................28

14 Full Copyright Statement.......................................29

Table of Tables
Table 1 - Information about the Delivery Method.....................6
Table 2 - Additional Subscription Template Attributes...............8
Table 3 - Printer Name in Event Notification Content...............16
Table 4 - Event Name in Event Notification Content.................17
Table 5 - Job Name in Event Notification Content...................17
Table 6 - Job State in Event Notification Content..................18
Table 7 - Printer State in Event Notification Content..............18

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1 Introduction

The "IPP Event Notifications and Subscriptions" document [ipp-ntfy]
defines an OPTIONAL extension to Internet Printing Protocol/1.0 (IPP)
[RFC2566, RFC2565] and IPP/1.1 [RFC2911, RFC2910] (for a description
of the base IPP documents, see section 13). That extension defines
operations that a client can perform in order to create Subscription
Objects in a Printer and carry out other operations on them. A
Subscription Object represents a Subscription abstraction. A client
associates Subscription Objects with a particular Job by performing
the Create-Job-Subscriptions operation or by submitting a Job with
subscription information. A client associates Subscription Objects
with the Printer by performing a Create-Printer-Subscriptions
operation. Four other operations are defined for Subscription
Objects: Get-Subscriptions-Attributes, Get-Subscriptions, Renew-
Subscription, and Cancel-Subscription. The Subscription Object
specifies that when one of the specified Events occurs, the Printer
sends an asynchronous Event Notification to the specified
Notification Recipient via the specified Delivery Method (i.e.,
protocol).

The "IPP Event Notifications and Subscriptions" document [ipp-ntfy]
specifies that each Delivery Method is defined in another document.
This document is one such document, and it specifies the 'mailto'
delivery method. When IPP Notification [ipp-ntfy] is supported, the
Delivery Method defined in this document is one of the RECOMMENDED
Delivery Methods and Printers to support.

For this Delivery Method, when an Event occurs, the Printer
immediately sends an Event Notification via an email message to the
Notification Recipient specified in the Subscription Object. The
message body of the email consists of Human Consumable text that is
not intended to be parsed by a machine. The 'mailto' Delivery Method
is a 'push' Delivery Method as defined in [ipp-ntfy].

The Notification Recipient receives the Event Notification in the
same way as it receives any other email message.

2 Terminology

This section defines the following terms that are used throughout
this document:

This document uses the same terminology as [RFC2911], such as
"client", "Printer", "attribute", "attribute value", "keyword",
"operation", "request", "response", and "support".

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Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD
NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to
conformance as defined in RFC 2119 [RFC2119] and [RFC2911] section
12.1. If an implementation supports the extension defined in this
document, then these terms apply; otherwise, they do not. These
terms define conformance to this document only; they do not affect
conformance to other documents, unless explicitly stated otherwise.

Capitalized terms, such as Notification Recipient, Event
Notification, Compound Event Notification, Printer, etc., are
defined in [ipp-ntfy], have the same meanings, and are not reproduced
here.

3 Model and Operation

In a Subscription Creation Operation, when the value of the "notify-
recipient-uri" attribute contains the URI scheme "mailto", the client
is requesting that the Printer use the 'mailto' Delivery Method for
Event Notifications generated from the new Subscription Object.

For this Delivery Method, the "notify-recipient-uri" attribute value
MUST consist of a "mailto" scheme followed by a colon, and then
followed by an address part (e.g., 'mailto:[email protected]'). See
section 5.2.1 for the syntax of the "notify-recipient-uri" attribute
value for this Delivery Method.

A Printer MUST support SMTP [RFC821], and it MAY support other email
protocols. A Printer MAY use additional services, such as SMTP
delivery status notification [RFC1891] or S/MIME encryption
[RFC2633].

If the client wants the Printer to send Event Notifications via the
'mailto' Delivery Method, the client MUST choose a value for "notify-
recipient-uri" attribute which conforms to the rules of section
5.2.1. To avoid denial-of-service attacks, a client SHOULD NOT use
distribution lists as the Notification Recipient.

When an Event occurs, the Printer MUST immediately:

1.Find all pertinent Subscription Objects P according to the rules
of section 9 of [ipp-ntfy], AND

2.Find the subset M of these Subscription Objects P whose "notify-
recipient-uri" attribute has a scheme value of 'mailto', AND

3.For each Subscription Object in M, the Printer MUST

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a)generate an email message as specified in section 5.2.2 AND

b)send the email message to the Notification Recipient specified
by the address part of the "notify-recipient-uri" attribute
value (see section 5.2.1).

If the Printer supports only SMTP, it MUST send the email message via
SMTP. If the Printer supports additional email protocols, it MUST
determine the protocol from the address part of the "notify-
recipient-uri" attribute value and then send the email message via
the appropriate email protocol.

When a Subscribing Client is subscribing to the 'job-progress' event
(which is a frequently occurring event), it SHOULD supply the
"notify-time-interval" attribute (see [ipp-ntfy]) in the Subscription
Creation request with a suitable value to limit the time between
'job-progress' Event Notifications sent by the Printer.

4 General Information

If a Printer supports this Delivery Method, the following are its
characteristics.

Table 1 - Information about the Delivery Method

Document Method Conformance Delivery Method Realization
Requirement

1. What is the URL scheme name for the mailto
Delivery Method?

2. Is the Delivery Method REQUIRED, RECOMMENDED
RECOMMENDED, or OPTIONAL for an IPP
Printer to support?

3. What transport and delivery A Printer MUST support
protocols does the Printer use to SMTP. It MAY support other
deliver the Event Notification email protocols.
Content, i.e., what is the entire
network stack?

4. Can several Event Notifications be A Printer implementation
combined into a Compound Event MAY combine several Event
Notification? Notifications into a single
email message (see section
6).
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email message (see section
6).

5. Is the Delivery Method initiated by This Delivery Method is a
the Notification Recipient (pull), push.
or by the Printer (push)?

6. Is the Event Notification content Human Consumable
Machine Consumable or Human
Consumable?

7. What section in this document Section 6
answers 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 the underlying SMTP
of the transport and delivery (or other optional) email
protocol? transport

9. What are the security aspects of the Same as the underlying SMTP
transport and delivery protocol, (or other optional) email
e.g., how it is handled in transport
firewalls?

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 See section 5.1.1 on
Subscription Template and/or "notify-mailto-text-only"
Subscription Description attributes
and the conformance requirements
thereof?
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and the conformance requirements
thereof?

13. What are the additional Printer None
Description attributes and the
conformance requirements thereof?

5 Subscription Template Attributes

5.1 Additional Subscription Template Attributes

This Delivery Method introduces one additional Subscription Template
Attribute (See Table 2).

Table 2 - Additional Subscription Template Attributes

Attribute in Subscription Object Default and Supported Printer
Attributes

notify-mailto-text-only (boolean) N/A

5.1.1 notify-mailto-text-only (boolean)

When the Printer generates an Event Notification from a Subscription
Object, this attribute specifies whether the Printer generates the
Event Notification with only plain text (i.e. 'text/plain') or with
Content-Types that the Printer chooses.

The Printer MUST support this attribute if it supports the 'mailto'
Delivery Method.

A client MAY supply this attribute. If a client does not supply this
attribute, the Printer MUST populate this attribute with the value of
'false' on the Subscription Object. There is no "notify-mailto-text-
only-default" attribute.

If the value of this attribute is 'true' in a Subscription Object,
the message body of each Event Notification that the Printer
generates from the Subscription Object MUST contain plain text only
(i.e. 'text/plain' with the charset specified by the "notify-charset'
Subscription Object attribute).

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If the value of this attribute is 'false' in a Subscription Object,
the Content-Type of the message body of each Event Notification that
the Printer generates from the Subscription Object MUST be either
'text/plain' or 'multipart', depending on implementation. If the
Content-Type is 'multipart', one message body of the 'multipart' MUST
be the same as the 'text/plain' message body when this attribute has
the value of 'true'. Each of the other message bodies of the
'multipart' MAY be any Content-Type (e.g. 'text/html', 'image/gif',
'audio/basic', etc.).

A Printer MUST support both values ('true' and 'false') of this
attribute. There is no "notify-mailto-text-only-supported" attribute.

5.2 Additional Information about Subscription Template Attributes

This section describes additional values for attributes defined in
[ipp-ntfy].

5.2.1 notify-recipient-uri (uri)

This section describes the syntax of the value of this attribute for
the 'mailto' 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 'mailto' Delivery Method, the Printer MUST
support the following syntax for the 'mailto' Delivery Method when
the Printer uses SMTP. The line below use RFC 822 syntax rules and
terms.

"mailto:" mailbox

Note: the above syntax allows 1 occurrence of 'mailbox'. The
occurrence of 'mailbox' represents an email address of a Notification
Recipient.

For SMTP, the phrase 'address part' of the "notify-recipient-uri"
attribute value refers to the 'mailbox' part of the value. Example:

mailto:[email protected]

Unlike other URLs, the mailto scheme MUST NOT use // after the colon
(see [RFC2368]).

The Printer MAY support other syntax for the 'address part' if it
supports email protocols in addition to SMTP.

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As noted in [ipp-ntfy], the uriScheme value of the corresponding
"notify-schemes-supported" Printer attribute does not include the ":"
character.

5.2.2 notify-user-data (octetString(63))

This attributes has a special use for the 'mailto' Delivery Method.
It specifies the email address of the Subscribing Client. It is
primarily useful when the Notification Recipient is some person other
than the Subscribing Client. Then the Notification Recipient has a
way to reply to the Subscribing Client.

If a client specifies this Delivery Method in a Subscription Creation
Operation, and the specified Notification Recipient is not associated
with the same person as the client, the client SHOULD supply its
email address as the value of the "notify-user-data" attribute. If
the client does not supply this attribute, the Printer MUST NOT
populate the Subscription Object with this attribute.

6 Event Notification Content

This section describes the content of an Event Notification sent via
the 'mailto' Delivery Method using the SMTP protocol. This document
does not describe the content for other email protocols, but an
implementation should use this section as a model.

When a Printer sends an email message via SMTP, the content MUST
conform to RFC 822. The following sections define the content that a
Printer MUST send. A Printer MAY send additional content as long as
the resulting content conforms to RFC 822.

While the "Event Notification Ordering" in [ipp-ntfy] section 9
specifies ordering requirements for Printers when sending separate
Event Notifications, email messages are not guaranteed to arrive in
the order sent so that the Notification Recipient may not receive
them in the same order.

Each subsection below specifies the syntax that pertains to the
subsection. The syntax rules and syntactic terms (e.g. 'date-time')
in each subsection come from RFC 822, except for the section on
"Content-Type" which comes from RFC 1521.

The Event Notification content has two parts, the headers and the
message body. The headers precede the message body and are separated
by a blank line (see [RFC 822]).

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A Printer implementation MAY combine several Event Notifications into
a single email message body. Such an email message is considered a
single Compound Event Notification and MUST follow the "Event
Notification Ordering" requirements for Event Notifications within a
Compound Event Notification specified in [ipp-ntfy] section 9.

6.1 Headers

When a Printer sends an Event Notification via SMTP, it MUST include
the following headers. RFC 822 RECOMMENDS that the headers be in the
order that they appear below.

6.1.1 'Date' header

Syntax: "Date" ":" date-time

This header contains the date and time that the Event occurred.

The Printer MUST include a "Date" header if and only if it supports
the "printer-current-time" Printer attribute.

6.1.2 'From' header

Syntax: "From" ":" mailbox

where

mailbox = addr-spec / phrase route-addr

This header causes a typical email reader to show the email as coming
from the Printer that is sending the Event Notification.

The Printer MUST include a "From" header whose syntax is specified
above.

The Printer MUST use the second alternative of the syntax for
'mailbox' defined above (i.e. 'phrase route-addr'). The 'phrase' is
the Printer's display name and it MUST be the value of the "printer-
name" Printer attribute. The 'route-addr' MUST contain an email
address (inside angle brackets) belonging to either an administrator
or the output-device. This email address NEED NOT be capable of
receiving mail. There is no Printer attribute to hold this email
address, so that it cannot be configured using the IPP protocol
without an implementation-defined attribute extension.

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6.1.3 'Subject' header

Syntax: "Subject" ":" *text

This header specifies the subject of the message and contains a short
summary of the Event Notification.

The Printer MUST include a "Subject" header whose syntax is specified
above.

The Printer MUST localize the '*text' using the values of the
"notify-charset" and "notify-natural-language" Subscription Object
attributes.

For Printer Events, the '*text' SHOULD start with the localized word
"printer:", followed by the Printer name, and then followed by the
localized Event name, e.g., in English: "printer: 'tiger' stopped" or
in Danish: "Printeren 'tiger' er standset".

For Job Events, the '*text' SHOULD start with the localized phrase
"print job:", followed by the Job name, and then followed by the
localized Event name, e.g., in English: "print job: 'financials'
completed".

The wording is implementation dependent. A Notification Recipient
MUST NOT expect to be able to parse this text. But an email filter
might look for "printer" or "print job".

6.1.4 'Sender' header

Syntax: "Sender" ":" mailbox

This header causes a typical email reader to show the email as coming
on behalf of the person associated with the Subscribing Client.

If the Subscription Object contains the "notify-user-data" attribute,
and if its value satisfies the RFC 822 syntax rules for 'mailbox',
the Printer MUST include a "Sender" header whose syntax is specified
above. Otherwise, the Printer MUST NOT include a "Sender" header.

For the "Sender" header, the 'mailbox' MUST be the value of the
"notify-user-data" Subscription Object attribute. See section 5.2.2
for details about the "notify-user-data" attribute.

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6.1.5 'Reply-to' header

Syntax: "Reply-to" ":" mailbox

If the Notification Recipient replies to Event Notification email,
this header causes a typical email reader to send email to the person
acting as the Subscribing Client. The rules are identical to the
"Sender" header.

If the Subscription Object contains the "notify-user-data" attribute,
and if its value satisfies the RFC 822 syntax rules for "mailbox",
the Printer MUST include a "Reply-to" header whose syntax is
specified above. Otherwise, the Printer MUST NOT include a "Reply-to"
header.

For the "Reply-to" header, the "mailbox" MUST be the value of the
"notify-user-data" Subscription Object attribute. See section 5.2.2
for details about the "notify-user-data" attribute.

6.1.6 'To' header

Syntax: "To" ":" 1#mailbox

See [RFC 1521] for the syntax.

This header specifies the Notification Recipient(s).

The Printer MUST include a "To" header whose syntax is specified
above.

The '1#mailbox' MUST be the '1#mailbox' part of the value of the
"notify-recipient-uri" Subscription attribute, i.e. the part after
the "mailto:".

6.1.7 'Content-type' header

Syntax: "Content-Type" ":" type "/" subtype *(";"parameter)

See [RFC 1521] for the syntactic terms (e.g. 'type').

This header specifies the format of the message body.

The Printer MUST include the "Content-Type" header.

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The "notify-mailto-text-only" attribute determines the 'type' and
'subtype' values. The possible values are "text/plain" and
"multipart" values.

6.2 Message Body

The message body MUST contain Human Consumable content as plain text.
It MAY also contain other types of implementation dependent content.

For plain text, the Content-Type of Human Consumable content MUST be
'text/plain'. For implementation dependent content, the Content-Type
of Human Consumable content MUST be 'multipart'. The Content-Type of
one body part MUST be 'text/plain' and the Content-Types of the other
body parts are implementation dependent. See section 6.3 for a
description of plain text content.

The following table shows the Content-Type of the message body for
the "notify-mailto-text-only" attribute:

"notify- Content-Type of Message Body
mailto-text- Message Body
only"
attribute

false 'text/plain' Human Consumable

true 'text/plain' or* Human Consumable plain text

'multipart' Human Consumable where one
body part is plain text

* The Content-Type depends on the implementation. A Printer MAY send
'text/plain' only or it MAY send several body parts of various
Content-Types within a message body whose Content-Type is
'multipart'.

6.3 Plain Text Content

When a Printer sends a plain text message, it MUST localize the text
using the values of the "notify-charset" and "notify-natural-
language" Subscription Object attributes.

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Section 9.2 in [ipp-ntfy] specifies the information that a Delivery
Method MUST specify and a Printer SHOULD send.

A Printer SHOULD send the following localized information in the
message body. The specific wording of this information and its layout
are implementation dependent.

a)the Printer name (see Table 3)
b)omitted (see below).
c)for Printer Events only:
i) the Event (see Table 4) and/or Printer state information
(see Table 7)
d)for Job Events only:
i) the job identity (see Table 5)
ii) the Event (see Table 4) and/or Job state information (see
Table 6)

Item b) in the above list is omitted because the Printer sends the
time of the Event as an email header (see section 6.1.1 on the
'Date' header).

The subsections of this section specify the attributes that a Printer
MUST use to obtain this information.

The Printer MAY send additional information, depending on
implementation.

Notification Recipients MUST NOT expect to be able to parse the
message.

The next three sections define the attributes in Event Notification
Contents that are:

a)for all Events

b)for Job Events only

c)for Printer Events only

6.3.1 Event Notification Content Common to All Events

The Printer MUST send the following information.

There is a separate table for each piece of information. Each row in
the table represents a source value for the information and the
values are listed in order of preference, with the first one being
the preferred one. An implementation SHOULD use the source value from

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the earliest row in each table. It MAY use the source value from
another row instead, or it MAY combine the source values from several
rows. An implementation is free to determine the best way to present
this information.

The tables in this section and following sections contain the
following columns for each piece of information:

a)Source of Value: the name of the attribute that supplies the
value for the Event Notification

b)Sends:

MAY: this is the only value used in the tables. It means that
the Printer OPTIONALLY sends this value. However, the Printer
SHOULD use at least one value from each table.

c)Source Object: the object from which the source value comes.

Table 3 lists the source of the information for the Printer Name. The
"printer-name" is more user-friendly unless the Notification
Recipient is in a place where the Printer name is not meaningful. For
example, an implementation could have the intelligence to send the
value of the "printer-name" attribute to a Notification Recipient
that can access the Printer via value of the "printer-name" attribute
and otherwise send the value of the "notify-printer-uri" attribute.

Table 3 - Printer Name in Event Notification Content

Source Value Sends Source Object

printer-name (name(127)) MAY Printer

notify-printer-uri (uri) MAY Subscription

Table 4 lists the source of the information for the Event name. A
Printer MAY combine this information with state information described
for Jobs in Table 6 or for Printers in Table 7.

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Table 4 - Event Name in Event Notification Content

Source Value Sends Source Object

notify-subscribed-event (type2 keyword) MAY Subscription

6.3.2 Additional Event Notification Content for Job Events

This section lists the source of the additional information that a
Printer MUST send for Job Events.

Table 5 lists the source of the information for the job name. The
"job-name" is likely more meaningful to a user than "job-id".

Table 5 - Job Name in Event Notification Content

Source Value Sends Source Object

job-name (name(MAX)) MAY Job

job-id (integer(1:MAX)) MAY Job

Table 6 lists the source of the information for the job-state. If a
Printer supports the "job-state-message" and "job-detailed-state-
message" attributes, it SHOULD use those attributes for the job state
information, otherwise, it should fabricate such information from the
"job-state" and "job-state-reasons". For some Events, a Printer MAY
combine this information with Event information.

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Table 6 - Job State in Event Notification Content

Source Value Sends Source Object

job-state-message (text(MAX)) MAY Job

job-detailed-status-messages (1setOf Job
text(MAX)) MAY

job-state (type1 enum) MAY Job

job-state-reasons (1setOf type2 keyword) MAY Job

6.3.3 Additional Event Notification Content for Printer Events

This section lists the source of the additional information that a
Printer MUST send for Printer Events.

Table 7 lists the source of the information for the printer-state. If
a Printer supports the "printer-state-message", it SHOULD use that
attribute for the job state information, otherwise it SHOULD
fabricate such information from the "printer-state" and "printer-
state-reasons". For some Events, a Printer MAY combine this
information with Event information.

Table 7 - Printer State in Event Notification Content

Source Value Sends Source Object

printer-state-message (text(MAX)) MAY Printer

printer-state (type1 enum) MAY Printer

printer-state-reasons (1setOf type2 MAY Printer
keyword)

printer-is-accepting-jobs (boolean) MAY Printer

6.4 Examples

This section contains three examples. One is a Job Event and the
other two are Printer Events, the latter in Danish.

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A Printer implementation NEED NOT generate Event Notification content
that is identical or even similar to these examples. In fact it would
be unfortunate if every implementation copied these example as is.
These examples merely show some possibilities and are not necessarily
the best way to convey information about an Event.

6.4.1 Job Event Example

This section contains an example of an Event Notification of a Job
Event.

A Subscribing Client Mike Jones (who works for xyz Corp.) performs a
Subscription Creation Operation as part of the Print-Job operation on
Printer "ipp://[email protected]". Mike Jones specifies that the "job-
name" is "financials". Mike is printing the Job for Bill Smith at abc
Corp. The Subscription Object then has the following attributes:

Attribute Name Attribute Value

notify-recipient-uri mailto:[email protected]

notify-events job-completed

notify-user-data [email protected]

notify-mailto-text-only true

notify-charset us-ascii

notify-natural-language en-us

notify-subscription-id 35692

notify-sequence-number 0

notify-printer-up-time 34593

notify-printer-uri ipp://[email protected]

notify-job-id 345

notify-subscriber-user-name mjones

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When the Job completes, the Printer generates and sends the following
email message:

Date: 17 Jul 00 1632 PDT
From: tiger <[email protected]>
Subject: print job: 'financials' completed
Sender: [email protected]
Reply-to: [email protected]
To: [email protected]
Content-type: text/plain

printer: tiger
job: financials
job-state: completed

The reader should note that the phrases are not identical to IPP
keywords. They have been localized to English.

6.4.2 Printer Event Example

This section contains an example of an Event Notification of a
Printer Event.

A Subscribing Client Peter Williams, a Printer admin, performs a
Create-Printer-Subscriptions operation on Printer
"ipp://[email protected]". The Subscription Object then has the following
attributes:

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Attribute Name Attribute Value

notify-recipient-uri mailto:[email protected]

notify-events printer-state-changed

notify-mailto-text-only true

notify-charset us-ascii

notify-natural-language en-us

notify-subscription-id 4623

notify-sequence-number 0

notify-printer-uptime 23002

notify-printer-uri ipp://[email protected]

notify-lease-expiration-time 0

notify-subscriber-user-name pwilliams

When the Printer jams, the Printer generates and sends the following
email message:

Date: 29 Aug 00 0832 PDT
From: tiger <[email protected]>
Subject: printer: 'tiger' has stopped
To: [email protected]
Content-type: text/plain

Printer tiger has stopped with a paper jam.

The reader should note that the phrases are not identical to IPP
keywords. They have been localized to English.

6.4.3 Printer Event Example (localized to Danish)

This section contains an example of an Event Notification of a
Printer Event localized to Danish.

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A Subscribing Client Per Jensen, a Printer admin, performs a Create-
Printer-Subscriptions operation on Printer "ipp://[email protected]". The
Subscription Object then has the following attributes:

Attribute Name Attribute Value

notify-recipient-uri mailto:[email protected]

notify-events printer-state-changed

notify-mailto-text-only true

notify-charset utf-8

notify-natural-language da

notify-subscription-id 50225

notify-sequence-number 0

notify-printer-uptime 53217

notify-printer-uri ipp://[email protected]

notify-lease-expiration-time 0

notify-subscriber-user-name pjensen

When the Printer jams, the Printer generates and sends the following
email message:

Date: 29 Jan 00 0832 CET
From: tiger <[email protected]>
Subject: Printeren 'tiger' er standset
To: [email protected]
Content-type: text/plain;charset=utf-8

Printerens navn er 'tiger'.
Printeren er standset.
Aarsagen er papir stop.

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7 Conformance Requirements

The 'mailto' Delivery Method is RECOMMENDED for a Printer to support.

If the Printer supports the 'mailto' Delivery Method, the Printer
MUST:

1.meet the conformance requirements defined in [ipp-ntfy].

2.support the "notify-mailto-text-only" Subscription Object
attribute defined in section 5.1.1.

3.support the syntax for the "notify-recipient-uri" Subscription
Object attribute defined in section 5.2.1

4.support the use for the "notify-user-data" Subscription Object
attribute defined in section 5.2.2

5.support SMTP for sending Event Notifications.

6.support the 'text/plain' Content-Type for the message body.

7.support sending Event Notification via email with the content
specified in section 5.2.

8 IANA Considerations

Because the 'mailto' URL scheme is already defined in a standards
track document [RFC 2368] and has been registered with IANA as a URL
scheme, this document does not require that the mailto URL scheme be
further registered as a protocol scheme.

The rest of this section contains the exact registration information
for IANA to add to the various IPP Registries according to the
procedures defined in RFC 2911 [RFC2911] section 6 to cover the
definitions in this document.

Note to RFC Editors: Replace RFC NNNN below with the RFC number
for this document, so that it accurately reflects the content of
the information for the IANA Registry.

8.1 Attribute Registration

The following table lists the attribute defined in this document.
This is to be registered according to the procedures in RFC 2911
[RFC2911] section 6.2.

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Subscription Template attributes: Ref. Section:
notify-mailto-text-only (boolean) RFC NNNN 5.1.1

The resulting attribute registration will be published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attributes/

area.

8.2 Additional uriScheme Attribute Value Registration for the
"operations-supported" Printer Attribute

The following table lists the uriScheme value defined in this
document as an additional uriScheme value for use with the "notify-
schemes-supported" Printer attribute defined in [ipp-ntfy]. This is
to be registered according to the procedures in RFC 2911 [RFC2911]
section 6.1.

uriScheme Attribute Values: Ref. Section:
mailto RFC NNNN 5.2.1

The resulting uri scheme attribute value registration will be
published in the
ftp://ftp.iana.org/in-notes/iana/assignments/ipp/attribute-

values/notify-schemes-supported/
area.

9 Internationalization Considerations

This Delivery Method presents no internationalization considerations
beyond those covered in the [ipp-ntfy] document, and sections 6.1.3
and 6.2 of this document.

The Notification Recipient is expected to present the email as
received because the Printer does all necessary localization to the
Event Notification contents.

10 Security Considerations

The biggest security concern is that a Subscribing Client will cause
unsolicited Event Notifications to be sent to third parties,
potentially creating denial-of-service problems (i.e., spam). The
problem is even worse if the third parties are distribution lists.

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There exist scenarios where third party notification is required (see
Scenario #2 and #3 in [ipp-not-req]). The fully secure solution
would require active agreement of all persons before they can become
Notification Recipients. However, requirement #9 in [ipp-req]
("There is no requirement for IPP Printer receiving the print request
to validate the identity of an event recipient") argues against this.
To minimize the risk, a Printer could disallow third party
Notification Recipients (a traditional facsimile model).

The Delivery Method recommends that the Subscribing Client supply his
or her email address as the value of the "notify-user-data" attribute
in the Subscription Creation Operation when the Notification
Recipient is a third party. To reduce the chance of spamming or
identify the spammer, a Printer could disallow third party
Notification Recipients if the Subscribing Client doesn't supply the
"notify-user-data" attribute with a valid email address.

Some firewall administrators prevent mail attachments from being
accepted into their organizations because of the problem of the
attachments containing computer viruses. The 'mailto' Delivery
Method allows the Subscribing Client to request that the Content-Type
of a message body be 'text/plain'.

11 References

[ipp-iig]
Hastings, T., Manros, C., Kugler, K, Holst H., Zehler, P.,
"Internet Printing Protocol/1.1: draft-ietf-ipp-implementers-
guide-v11-03.txt, work in progress, July 17, 2001.

[ipp-ntfy]
Herriot, R., Hastings, T., Isaacson, S., Martin, J., deBry, R.,
Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP
Event Notifications and Subscriptions", <draft-ietf-ipp-not-spec-
07.txt>, July 17, 2001.

[RFC821]
Jonathan B. Postel, "Simple Mail Transfer Protocol", RFC 821,
August, 1982.

[RFC822]
David H. Crocker, "Standard For The Format Of ARPA Internet Text
Messages", RFC 822, August 13, 1982.

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[RFC1341]
N. Borenstein, N. Freed, "MIME (Multipurpose Internet Mail
Extensions): Mechanisms for Specifying and Describing the Format of
Internet Message Bodies", RFC 1341, June, 1992.

[RFC1521]

N. Borenstein, N. Freed, "MIME (Multipurpose Internet Mail
Extensions) Part One: Mechanisms for Specifying and Describing the
Format of Internet Message Bodies", RFC 1521, September 1993.

[RFC1891]
K. Moore, "SMTP Service Extension for Delivery Status
Notifications", RFC 1891, January 1996

[RFC2026]
S. Bradner, "The Internet Standards Process -- Revision 3", RFC
2026, October 1996.

[RFC2046]
R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P.
Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1",
RFC 2616, June 1999.

[RFC2368]
P. Hoffman, L. Masinter, J. Zawinski, "The mailto URL scheme", RFC
2368, July 1998.

[RFC2616]
R. Fielding, J. Gettys, J. Mogul, H. Frystyk, L. Masinter, P.
Leach, T. Berners-Lee, "Hypertext Transfer Protocol - HTTP/1.1",
RFC 2616, June 1999.

[RFC2633]
B. Ramsdell, "S/MIME Version 3 Message Specification", RFC 2633,
June 1999.

[RFC2910]
Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
Protocol/1.1: Encoding and Transport", RFC 2910, September, 2000.

[RFC2911]
R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell,
"Internet Printing Protocol/1.0: Model and Semantics", RFC 2911,
September, 2000.

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12 Author's Addresses

Robert Herriot
Xerox Corporation
3400 Hillview Ave., Bldg #1
Palo Alto, CA 94304

Phone: 650-813-7696
Fax: 650-813-6860
Email: [email protected]

Henrik Holst
i-data international a/s
Vadstrupvej 35-43
2880 Bagsvaerd, Denmark

Phone: +45 4436-6000
Fax: +45 4436-6111
e-mail: [email protected]

Tom Hastings
Xerox Corporation
737 Hawaii St. ESAE 231
El Segundo, CA 90245

Phone: 310-333-6413
Fax: 310-333-5514
e-mail: [email protected]

Carl-Uno Manros
Xerox Corporation
737 Hawaii St. ESAE 231
El Segundo, CA 90245

Phone: 310-333-8273
Fax: 310-333-5514
e-mail: [email protected]

IPP Web Page: http://www.pwg.org/ipp/
IPP Mailing List: [email protected]

To subscribe to the ipp mailing list, send the following email:
1) send it to [email protected]
2) leave the subject line blank

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3) put the following two lines in the message body:
subscribe ipp
end

Implementers of this specification document are encouraged to join
IPP Mailing List in order to participate in any discussions of
clarification issues and review of registration proposals for
additional attributes and values. In order to reduce spam the
mailing list rejects mail from non-subscribers, so you must subscribe
to the mailing list in order to send a question or comment to the
mailing list.

13 Summary of Base IPP Documents

The base set of IPP documents includes:

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 [ipp-iig]
Mapping between LPD and IPP Protocols [RFC2569]
Internet Printing Protocol (IPP): IPP Event Notifications and
Subscriptions [ipp-ntfy]

The "Design Goals for an Internet Printing Protocol" document takes a
broad look at distributed printing functionality, and it enumerates
real-life scenarios that help to 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. A few OPTIONAL operator operations have
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.

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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 'ippget' 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.

The "IPP Event Notifications and Subscriptions" document defines an
extension to IPP/1.0 [RFC2566, RFC2565] and IPP/1.1 [RFC2911,
RFC2910]. This extension allows a client to subscribe to printing
related Events and defines the semantics for delivering asynchronous
Event Notifications to the specified Notification Recipient via a
specified Delivery Method (i.e., protocols) defined in (separate)
Delivery Method documents.

14 Full Copyright Statement

Copyright (C) The Internet Society (2000). 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.

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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

Funding for the RFC Editor function is currently provided by the
Internet Society.

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