INTERNET-DRAFT There are 4 issues Hugo Parra Novell, Inc. Tom Hastings Xerox Corp. July 6, 2000 Internet Printing Protocol (IPP): The 'indp' Notification Delivery Method 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 areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed as http://www.ietf.org/shadow.html. Abstract The IPP Event Notification specification [ipp-ntfy] is an OPTIONAL extension to IPP/1.0, IPP/1.1, and future versions. [ipp-ntfy] requires the definition of one or more Delivery Methods in separate Delivery Method Documents for the Printer to dispatch Event Notifications to Notification Recipients. This Delivery Method Document defines the semantics and syntax of the 'indp' Notification Delivery Method. For this Delivery Method, an IPP Printer sends (pushes) an IPP Event Notifications request to the Notification Recipients using the Send- Notifications operation defined in this document. The Notification Recipient returns a response to the Printer. The Send-Notifications operation uses the same Encoding and Transport as IPP itself. Parra, Hastings [page 1] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 The full 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 [ipp-mod] Internet Printing Protocol/1.1: Encoding and Transport [ipp-pro] Internet Printing Protocol/1.1: Implementer's Guide [ipp-iig] Mapping between LPD and IPP Protocols [RFC2569] Internet Printing Protocol (IPP): IPP Event Notification Specification [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: 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 a message body over HTTP whose Content-Type is "application/ipp". This document defines a new scheme named 'ipp' 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 "Internet Printing Protocol (IPP): IPP Event Notification Specification" document defines the semantics for Subscription Creation Operations and the requirements for other Delivery Method documents to define a Delivery Method to carry an Event Notifications to a Notification Recipient. Parra, Hastings [page 2] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 Table of Contents 1 Introduction......................................................5 2 Terminology.......................................................5 3 Model and Operation...............................................5 4 Summary of the 'indp' Delivery Method.............................6 5 Subscription object attributes....................................8 5.1SUBSCRIPTION TEMPLATE ATTRIBUTE CONFORMANCE......................8 5.2SUBSCRIPTION DESCRIPTION ATTRIBUTE CONFORMANCE...................8 6 Printer Description Attribute Conformance.........................9 7 New Values for Existing Printer Description Attributes............9 7.1NOTIFY-SCHEMES-SUPPORTED (1SETOF URISCHEME)......................9 7.2OPERATIONS-SUPPORTED (1SETOF TYPE2 ENUM).........................9 0X001D..............................................................9 8 Attributes Only in Event Notifications............................9 9 Operations for Notification.......................................9 9.1SEND-NOTIFICATIONS OPERATION....................................10 9.1.1 Send-Notifications Request.................................10 9.1.2 Send-Notifications Response................................13 9.2NOTIFICATION PROTOCOL URI SCHEME................................14 10 Status Codes.....................................................15 10.1 ADDITIONAL STATUS CODES.......................................15 10.1.1 successful-ok-ignored-notifications (0x0004)..............15 10.2 STATUS CODES RETURNED IN EVENT NOTIFICATION ATTRIBUTES GROUPS.15 10.2.1 client-error-not-found (0x0406)...........................15 10.2.2 successful-ok-but-cancel-subscription (0x0006)............16 11 Encoding and Transport...........................................16 11.1 ENCODING OF THE OPERATION LAYER...............................16 11.2 ENCODING OF TRANSPORT LAYER...................................16 12 IANA Considerations..............................................16 13 Internationalization Considerations..............................16 14 Security Considerations..........................................17 14.1 SECURITY CONFORMANCE..........................................17 15 References.......................................................17 16 Author's Addresses...............................................18 Parra, Hastings [page 3] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 17 Full Copyright Statement.........................................18 Tables Table 1 - Summary of the 'indp' Delivery Method.......................6 Table 2 . Operation-id assignments....................................9 Table 3 . Attributes in Event Notification Content...................11 Table 4 . Additional Attributes in Event Notification Content for Job Events............................................................12 Table 5 . Combinations of Events and Subscribed Events for .job- impressions-completed............................................13 Table 6 . Additional Attributes in Event Notification Content for Printer Events...................................................13 Parra, Hastings [page 4] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 1 Introduction The notification extension document [ipp-ntfy] 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. 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 notification extension document [ipp-ntfy] specifies that each Delivery Method is defined in another document. This document is one such document, and it specifies the .indp. Delivery Method. For the .indp. Delivery Method, an IPP Printer sends (pushes) a Send- Notifications operation request containing one or more Event Notifications to a Notification Recipient. The Notification Recipient returns a response to the Printer. The Send-Notifications operation uses the same Encoding and Transport as IPP itself. 2 Terminology This document uses terms such as "attributes", "keywords", and "support". These terms have special meaning and are defined in the model terminology [ipp-mod] section 12.2. Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD, SHOULD NOT, MAY, NEED NOT, and OPTIONAL, have special meaning relating to conformance. These terms are defined in [ipp-mod] section 12.1 on conformance terminology, most of which is taken from RFC 2119 [RFC2119]. This document uses the capitalized terms, such as Notification Recipient, Event Notification, Printer, etc., that are defined in [ipp- ntfy] with the same meanings and are not reproduced here. This section defines the following additional terms that are used throughout this document: Event Notification Attributes Group . The attributes group in a request that contains Event Notification Attributes in a request or response. 3 Model and Operation See [ipp-ntfy] for the description of the Event Notification Model and Operation. This Delivery Method takes advantage of combining several Event Notifications into a single Compound Event Notification that is delivery by a single Send-Notification operation to a single Notification Recipient. Parra, Hastings [page 5] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 When creating each Subscription object, the client supplies the "notify- recipient" (uri) Subscription Template attribute. The "notify- recipient" attribute specifies both a single Notification Recipient that is to receive the Notifications when subsequent events occur and the method for notification delivery that the IPP Printer is to use. For the Notification Delivery Method defined in this document, the notification method is 'indp' and the rest of the URI is the address of the Notification Recipient to which the IPP Printer will send the Send- Notifications operation. The 'indp' Notification Delivery Method defined in this document uses a client/server protocol paradigm. The "client" in this relationship is the Printer described in [ipp-ntfy] while the "server" is the Notification Recipient. The Printer invokes the Send-Notifications operation to communicate IPP Event Notification contents to the Notification Recipient. The Notification Recipient only conveys information to the Printer in the form of responses to the operations initiated by the Printer. Printers that implement the 'indp' Notification Delivery Method will need to include an HTTP client stack while Notification Recipients that implement this Delivery Method will need to support an HTTP server stack. See section 11.2 for more details. 4 Summary of the 'indp' Delivery Method Column 1 of Table 1 lists the conformance requirements for Delivery Method Documents as specified in [ipp-ntfy]. Column 2 indicates how this Delivery Method Document meets each requirement: Table 1 - Summary of the 'indp' Delivery Method Document Method conformance 'indp' realization requirement 1.MUST define a URL scheme indp name for the Delivery Method. 2.MUST indicate whether the OPTIONAL delivery method is REQUIRED or OPTIONAL for an IPP Printer to support if it supports Event Notification. 3.MUST define the transport a complete HTTP stack [rfc2616] and delivery protocol for the Event Notification content that a Printer MUST use, i.e., the entire network stack. 4.MUST indicate whether or not yes, see section 9.1.1 several Event Notifications can Parra, Hastings [page 6] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 Document Method conformance 'indp' realization requirement be combined into a compound Event Notification. 5.MUST describe how the initiated by the Printer (push) Delivery Method is initiated, i.e., is it initiated by the receiving user (pull), or is it initiated by the Printer (push). 6.MUST indicate whether the Machine Consumable with the Delivery Method is Machine "notify-text" attribute being Consumable or Human Consumable. Human Consumable 7.MUST define the The representation and encoding representation and encoding is the same as IPP. See that a Printer MUST use for section 9.1.1 each value or piece of information listed in [ipp- ntfy] section 9 (9.1 for Machine Consumable Event Notification and/or section 9.2 for Human Consumable Event Notification). 8.MUST specify for each See the Send-Notifications attribute in [ipp-ntfy] section Request defined in section 9 whether a Printer MUST, 9.1.1 SHOULD, MAY, MUST NOT, SHOULD NOT or NEED NOT send the attribute in an Event Notification content. 9.MUST define what frequently Frequently occurring Events occurring Events MUST be NEED NOT be moderated because moderated, if any, and whether the Delivery Method is an the moderation mechanism is efficient one and because the configurable. Also whether Printer can group multiple Events are moderated by sending Event Notifications for the one per time unit or one per same Notification Recipient number of Events. into a single Send- Notifications operations. 10. MUST discuss the latency Same as for IPP/1.0 or IPP/1.1 and reliability of the itself (see [ipp-mod]). transport and delivery protocol. 11. MUST discuss the security See section 14 aspects of the transport and Parra, Hastings [page 7] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 Document Method conformance 'indp' realization requirement delivery protocol, e.g., how it is handled in firewalls. 12. MUST identify content They are the same as for length restrictions, if any. IPP/1.0 and IPP/1.1 itself (see [ipp-mod]). 13. MAY define additional A new Event Notifications values or pieces of information attribute group (see section that a Printer MUST, SHOULD or 11.1) and additional status MAY send in a Notification codes for use in the response content. (see section 10) 14. MAY define additional none defined Subscription Template and/or Subscription Description attributes and the conformance requirements thereof. 15. MAY define additional none defined Printer Description attributes and the conformance requirements thereof. The remaining sections of this document parallel the sections of [ipp- ntfy]. 5 Subscription object attributes This section defines the Subscription object conformance requirements for Printers. 5.1 Subscription Template Attribute Conformance The 'indp' Delivery Method has the same conformance requirements for Subscription Template attributes as defined in [ipp-ntfy]. The 'indp' Delivery Method does not define any addition Subscription Template attributes. 5.2 Subscription Description Attribute Conformance The 'indp' Delivery Method has the same conformance requirements for Subscription Description attributes as defined in [ipp-ntfy]. The 'indp' Delivery Method does not define any addition Subscription Description attributes. Parra, Hastings [page 8] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 6 Printer Description Attribute Conformance The 'indp' Delivery Method has the same conformance requirements for Printer Description attributes as defined in [ipp-ntfy]. The 'indp' Delivery Method does not define any addition Printer Description attributes. 7 New Values for Existing Printer Description Attributes This section defines additional values for existing Printer Description attributes. 7.1 notify-schemes-supported (1setOf uriScheme) The following .notify-schemes-supported. value is added in order to support the new Delivery Method defined in this document: 'indp': - The IPP Notification Delivery Method defined in this document. 7.2 operations-supported (1setOf type2 enum) Table 2 lists the .operation-id. value added in order to support the new operation defined in this document. The operation-id is assigned in the same name space as other operations that a Printer supports. However, a Printer MUST NOT include this value in its "operations-supported" attribute unless it can accept the Send-Notifications request. Table 2 . Operation-id assignments Value Operation Name 0x001D Send-Notifications 8 Attributes Only in Event Notifications No additional attributes are defined only for use in Event Notifications besides those defined in [ipp-ntfy]. 9 Operations for Notification This section defines the operation for Event Notification using the 'indp' Delivery Method. There is only one operation defined: Send-Notifications. Section 7.2 assigns of the .operation-id. for the Send-Notifications operation and the following section defined the operation. Parra, Hastings [page 9] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 9.1 Send-Notifications operation This REQUIRED operation allows a Printer to send one or more Event Notifications to a Notification Recipient using HTTP. The Printer composes the information defined for an IPP Notification [ipp-ntfy] and sends it using the Sent-Notifications operation to the Notification Recipient supplied in the Subscription object. The Send-Notifications operations uses the operations model defined by IPP [rfc2566]. This includes, the use of a URI as the identifier for the target of each operation, the inclusion of a version number, operation-id, and request-id in each request, and the definition of attribute groups. The Send-Notifications operation uses the Operation Attributes group, but currently has no need for the Unsupported Attributes, Printer Object Attributes, and Job-Object Attributes groups. However, it uses a new attribute group, the Event Notification Attributes group. The Notification Recipient MUST accept the request in any state. There is no state defined for the Notification Recipient for this Delivery Method. Access Rights: To send Event Notifications to a Notification Recipient, the authenticated user (see [IPP-MOD] section 8.3) performing this operation MUST be the Printer that accepted a previous Subscription Creation operation (see [ipp-ntfy]). Otherwise the Notification Recipient MUST reject the operation and return: the .client-error- forbidden., .client-error-not-authenticated., or .client-error-not- authorized. status code as appropriate. ISSUE 01: Is this what the Access Rights section should say for a Send- Notifications request? 9.1.1 Send-Notifications Request Every operation request MUST contains the following parameters (see [ipp-mod] section 3.1.1): - a "version-number" ISSUE 02: What version number goes here? - an "operation-id" - the value defined in Table 2 - a "request-id" - the contents of the Subscription object's "notify-sequence-number" after incrementing for the first try (see [ipp-ntfy]). The following groups of attributes MUST be part of the Send- Notifications Request: Group 1: Operation Attributes Natural Language and Character Set: Parra, Hastings [page 10] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 The "attributes-charset" and "attributes-natural-language" attributes as defined in [ipp-mod] section 3.1.4.1. Target: A copy of the Subscription object's "notification-recipient- uri" (uri) attribute which is the target of this operation as described in [ipp-mod] section 3.1.5, i.e., the URI of the 'indp' Notification Recipient (see section 9.2). Requesting User Name: Unlike the other IPP operations, the .requesting-user-name. attribute SHOULD NOT be supplied by the client as described in [ipp-mod] section 8.3. ISSUE 03: Ok that "requesting-user-name" SHOULD NOT be send in Send-Notifications? Group 2 to N: Event Notification Attributes In each group 2 to N, each attribute is encoded using the IPP rules for encoding attributes [ipp-pro] and may be encoded in any order. Note: the Get-Jobs response in [ipp-mod] acts as a model for encoding multiple groups of attributes. Each Event Notification Group MUST contain all of attributes specified in [ipp-ntfy] section 9.1 (.Content of Machine Consumable Event Notifications.) with exceptions denoted by asterisks in the tables below. The tables below are copies of the tables in [ipp-ntfy] section 9.1 (.Content of Machine Consumable Event Notifications.) except that each cell in the .Sends. column is a .MUST.. For an Event Notification for all Events, the Printer sends the following attributes. Table 3 . Attributes in Event Notification Content Source Value Sends Source Object notify-subscription-id (integer(1:MAX)) MUST Subscription notify-printer-uri (uri) MUST Subscription notify-subscribed-event (type2 keyword) MUST Event Notification printer-up-time (integer(MIN:MAX)) MUST Printer printer-current-time (dateTime) * MUST Printer notify-sequence-number (integer (0:MAX)) MUST Subscription notify-charset (charset) MUST Subscription Parra, Hastings [page 11] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 Source Value Sends Source Object notify-natural-language (naturalLanguage) MUST Subscription notify-user-data (octetString(63)) ** MUST Subscription notify-text (text) MUST Event Notification attributes from the .notify-attributes. MUST Printer attribute *** attributes from the .notify-attributes. MUST Job attribute *** attributes from the .notify-attributes. MUST Subscription attribute *** ISSUE 04: Ok that "notify-text" has been changed from MAY to MUST? * The Printer MUST send .printer-current-time. if and only if it supports the .printer-current-time. attribute on the Printer object. ** If the associated Subscription Object does not contain a .notify-user-data. attribute, the Printer MUST send an octet-string of length 0. *** If the .notify-attributes. attribute is present on the Subscription Object, the Printer MUST send all attributes specified by the .notify-attributes. attribute. Note: if the Printer doesn.t support the .notify-attributes. attribute, it is not present on the associated Subscription Object. For Event Notifications for Job Events, the Printer sends the following additional attributes shown in Table 4. Table 4 . Additional Attributes in Event Notification Content for Job Events Source Value Sends Source Object job-id (integer(1:MAX)) MUST Job job-state (type1 enum) MUST Job job-state-reasons (1setOf type2 keyword) MUST Job job-impressions-completed MUST Job (integer(0:MAX)) * Parra, Hastings [page 12] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 * The Printer MUST send the .job-impressions-completed. attribute in an Event Notification only for the combinations of Events and Subscribed Events shown in Table 5. Table 5 . Combinations of Events and Subscribed Events for .job- impressions-completed. Job Event Subscribed Job Event .job-progress. .job-progress. .job-completed. .job-completed. .job-completed. .job-state-changed. For Event Notification for Printer Events, the Printer sends the following additional attributes shown in Table 6. Table 6 . Additional Attributes in Event Notification Content for Printer Events Source Value Sends Source Object printer-state (type1 enum) MUST Printer printer-state-reasons (1setOf type2 MUST Printer keyword) printer-is-accepting-jobs (boolean) MUST Printer 9.1.2 Send-Notifications Response The Notification Recipient MUST return (to the client which is the Printer) the following sets of attributes as part of a Send- Notifications response: Every operation response contains the following REQUIRED parameters (see [ipp-mod] section 3.1.1}: - a "version-number" - a "status-code" - the "request-id" that was supplied in the corresponding request Group 1: Operation Attributes Status Message: As defined in [ipp-mod]. Parra, Hastings [page 13] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 The Notification Recipient can return any status codes defined in [ipp-mod] and section 10.1 that applies to all of the Event Notification Attribute groups. The following is a description of the important status codes: 'successful-ok': the Notification Recipient received all of the Event Notification Attribute Groups and was expecting each of them. 'successful-ok-ignored-notifications': the Notification Recipient was able to consume some, but not all of the Event Notification Attributes Groups sent. The Event Notification Attributes Groups with a .notify-status-code. attribute are the ones that were ignored or are to be canceled. 'client-error-ignored-all-notifications': the Notification Recipient was unable to consume any of the Event Notification Attributes Groups sent. The Event Notification Attributes Groups with a .notify-status-code. attribute are the ones that were ignored or are to be canceled. Natural Language and Character Set: The "attributes-charset" and "attributes-natural-language" attributes as defined in [ipp-mod] section 3.1.4.1. Group 2 to N: Notification Attributes These groups MUST be returned if and only if the "status-code" parameter returned in Group 1 is anything but the 'successful-ok' status code. "notification-status-code" (type2 enum) Indicates whether the Notification Recipient was able to consume the n-th Notification Report as follows: 'successful-ok' - this Event Notification Attribute Group was consumed 'client-error-not-found' - this Event Notification Attribute Group was not able to be consumed. The Printer MUST cancel the Subscription and MUST NOT attempt to send any further Event Notifications from the associated Subscription object. 'successful-ok-but-cancel-subscription' - the Event Notification Attribute Group was consumed, but the Notification Recipient wishes to cancel the Subscription object. The Printer MUST cancel the Subscription and MUST NOT attempt to send any further Event Notifications from the associated Subscription object. 9.2 Notification Protocol URI Scheme The INDP Notification Delivery Method uses the 'indp://' URI scheme in the "notify-recipients" attribute in the Subscription object in order to indicate the notification Delivery Method defined in this document. The remainder of the URI indicates the host and address of the Notification Recipient that is to receive the Send-Notification operation. Parra, Hastings [page 14] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 10 Status Codes This section lists status codes whose meaning have been extended and/or defined for returning in Event Notification Attribute Groups as the value of the "notification-status-code" operation attribute. The code values are allocated in the same space as the status codes in [ipp-mod]. 10.1 Additional Status Codes The following status codes are defined as extensions for Notification and are returned as the value of the .status-code. parameter in the Operation Attributes Group of a response (see [ipp-mod] section 3.1.6.1). Operations in this document can also return the status codes defined in section 13 of [ipp-mod]. The .successful-ok. status code is an example of such a status code. 10.1.1 successful-ok-ignored-notifications (0x0004) The Notification Recipient was able to consume some, but not all, of the Event Notifications Attributes Groups sent by the Printer in the Send- Notifications request. See section 9.1.2 for further details. 10.2 Status Codes returned in Event Notification Attributes Groups This section contains values of the .notify-status-code. attribute that the Notification Recipient returns in a Event Notification Attributes Group in a response when the corresponding Event Notification Attributes Group in the request: 1. was not consumed OR 2. was consumed, but the Notification Recipient wants to cancel the corresponding Subscription object The following sections are ordered in decreasing order of importance of the status-codes. 10.2.1 client-error-not-found (0x0406) This status code is defined in [ipp-mod]. This document extends its meaning and allows it to be returned in an Event Notification Attributes Group of a response. The Notification Recipient was unable to consume this Event Notification Attributes Group because it was not expected. See section 9.1.2 for further details. Parra, Hastings [page 15] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 10.2.2 successful-ok-but-cancel-subscription (0x0006) The Notification Recipient was able to consume this Event Notification Attributes Group that the Printer sent, but wants the corresponding Subscription object to be canceled none-the-less. See section 9.1.2 for further details. 11 Encoding and Transport This section defines the encoding and transport used by the 'indp' Delivery Method. 11.1 Encoding of the Operation Layer The 'indp' Delivery Method uses the IPP operation layer encoding described in [ipp-pro] and the following Event Notification Attributes Group tag allocated by [ipp-ntfy]: Tag Value (Hex) Meaning 0x07 .event-notification-attributes-tag. 11.2 Encoding of Transport Layer The 'indp' Notification Delivery Method uses the IPP transport layer encoding described in [ipp-pro]. It is REQUIRED that an 'indp' Notification Recipient implementation support HTTP over the IANA assigned Well Known Port assigned to the 'indp' Delivery Method as its default port by IANA (see section 12), though a Notification Recipient implementation MAY support HTTP over some other port as well. 12 IANA Considerations The 'indp://' URL scheme for the 'indp' Delivery Method will be registered with IANA. IANA will assign a default port to use with the 'indp' Delivery Method. 13 Internationalization Considerations When the client requests Human Consumable form by supplying the "notify- text-format" operation attribute (see [ipp-ntfy]), the IPP Printer (or any Notification Service that the IPP Printer might be configured to use) supplies and localizes the text value of the "human-readable- report" attribute in the Notification according to the charset and natural language requested in the notification subscription. Parra, Hastings [page 16] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 14 Security Considerations The IPP Model and Semantics document [ipp-mod] discusses high level security requirements (Client Authentication, Server Authentication and Operation Privacy). Client Authentication is the mechanism by which the client proves its identity to the server in a secure manner. Server Authentication is the mechanism by which the server proves its identity to the client in a secure manner. Operation Privacy is defined as a mechanism for protecting operations from eavesdropping. The Notification Recipient can cancel unwanted Subscriptions created by other parties without having to be the owner of the subscription by returning the 'successful-ok-but-cancel-subscription' status code in the Send-Notifications response returned to the Printer. 14.1 Security Conformance Printers (client) MAY support Digest Authentication [rfc2617]. If Digest Authentication is supported, then MD5 and MD5-sess MUST be supported, but the Message Integrity feature NEED NOT be supported. Notification Recipient (server) MAY support Digest Authentication [rfc2617]. If Digest Authentication is supported, then MD5 and MD5-sess MUST be supported, but the Message Integrity feature NEED NOT be supported. Notification Recipients MAY support TLS for client authentication, server authentication and operation privacy. If a Notification Recipient supports TLS, it MUST support the TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA cipher suite as mandated by RFC 2246 [rfc2246]. All other cipher suites are OPTIONAL. Notification recipients MAY support Basic Authentication (described in HTTP/1.1 [rfc2616]) for client authentication if the channel is secure. TLS with the above mandated cipher suite can provide such a secure channel. 15 References [indp] Parra, H., T. Hastings, "Internet Printing Protocol (IPP): IPP Notification Delivery Protocol (INDP)", , February 29, 2000. [ipp-mod] R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell, "Internet Printing Protocol/1.0: Model and Semantics", , May 22, 2000. [ipp-ntfy] Isaacson, S., Martin, J., deBry, R., Hastings, T., Shepherd, M., Bergman, R., "Internet Printing Protocol/1.1: IPP Event Notification Specification", , June 30, 2000. Parra, Hastings [page 17] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 [ipp-pro] Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing Protocol/1.1: Encoding and Transport", draft-ietf-ipp-protocol-v11- 06.txt, May 30, 2000. [rfc2026] S. Bradner, "The Internet Standards Process -- Revision 3", RFC 2026, October 1996. [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. [rfc2617] J. Franks, P. Hallam-Baker, J. Hostetler, S. Lawrence, P. Leach, A. Luotonen, L. Stewart, "HTTP Authentication: Basic and Digest Access Authentication", RFC 2617, June 1999. 16 Author's Addresses Hugo Parra Novell, Inc. 1800 South Novell Place Provo, UT 84606 Phone: 801-861-3307 Fax: 801-861-2517 e-mail: hparra@novell.com Tom Hastings Xerox Corporation 737 Hawaii St. ESAE 231 El Segundo, CA 90245 Phone: 310-333-6413 Fax: 310-333-5514 e-mail: hastings@cp10.es.xerox.com 17 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 Parra, Hastings [page 18] Expires: January 6, 2001 INTERNET-DRAFT IPP: The INDP Notification Delivery MethodJuly 6, 2000 which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Parra, Hastings [page 19] Expires: January 6, 2001