Network Working Group H. Sugano
INTERNET-DRAFT S. Fujimoto
Fujitsu
G. Klyne
Baltimore Technologies
A. Bateman
VisionTech
Expires: April 2002 October 2001
CPIM Presence Information Data Format
<draft-ietf-impp-cpim-pidf-01.txt>
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
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Internet-Drafts are draft documents valid for a maximum of six months
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Please send comments to the authors or to the impp@iastate.edu
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Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This memo specifies CPIM Presence Information Data Format (PIDF) as a
common presence data format for CPIM-compliant IM/Presence protocols.
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Table of Content
1. Introduction ......................................... 3
1.1. Terminology and Conventions .......................... 3
2. Design Decisions ..................................... 3
2.1. Minimal Model ........................................ 3
3. Overall Presence Information Data Structure .......... 4
3.1. The 'application/cpim-pidf+xml' Content Type ......... 5
3.2. Combining Multiple Presence Documents ................ 5
4. XML-encoded Presence Data Format ..................... 6
4.1. XML Format Definitions ............................... 6
4.1.1. The <presence> element ............................... 6
4.1.2. The <presentity> element ............................. 6
4.1.3. The <tuple> element .................................. 6
4.1.4. The <status> element ................................. 7
4.1.5. The <value> element .................................. 7
4.1.6. The <contact> element ................................ 7
4.1.7. The <note> element ................................... 7
4.1.8. The <timestamp> element .............................. 8
4.2. Presence Information Extensibility ................... 8
4.2.1. XML Namespaces Background ............................ 8
4.2.2. XML Namespaces In Presence Information ............... 9
4.2.3. Handling Of Unrecognized Element Names ............... 9
4.3. Examples ............................................. 10
4.3.1. Default Namespace And No Extensions .................. 10
4.3.2. Example Presence Information Extensions .............. 11
4.3.3. Example Mandatory To Understand Extensions ........... 11
4.4. DTD .................................................. 12
5. Wrapping 'application/cpim-pidf+xml' Data ............ 13
5.1. When Used With 'message/cpim' ........................ 13
5.1.1. The 'From' header .................................... 13
5.1.2. The 'To' header ...................................... 13
5.1.3. The 'DateTime' header ................................ 13
5.1.4. The 'NS' header ...................................... 14
5.1.5. The 'Require' header ................................. 14
5.2. When Used With 'multipart/mixed' ..................... 14
5.2.1. The 'Presence-Data-ID' header ........................ 14
5.3. Examples ............................................. 14
6. Security Considerations .............................. 15
7. IANA Considerations .................................. 16
8. References ........................................... 16
9. Author's Addresses ................................... 17
10. Full Copyright Statement ............................ 18
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1. Introduction
The IMPP working group has been working to develop the Common Profile
for Instant Messaging (CPIM) specifications to achieve
interoperability of IM and Presence services between different
protocol domains. The the CPIM core document [CPIM] defines a set of
common operations and their parameters to be supported by
interworking IM/Presence protocols. The work on CPIM Message Format
[CPIM-MSG] defines a common format for instant messages, which
enables secure end-to-end IM exchange.
This memo defines the CPIM Presence Information Data Format (PIDF) as
a common presence data format for CPIM-compliant IM/Presence
protocols. Encoded in the common format, presence data can be
securely transferred across the boundary of different protocol
domains by utilizing digital signature and/or encryption.
1.1. Terminology and Conventions
This memos makes use of the vocabulary defined in the IMPP Model
document [RFC2778]. Terms such as as CLOSED, INSTANT INBOX, INSTANT
MESSAGE, OPEN, PRESENCE SERVICE, PRESENTITY, SUBSCRIPTION, and
WATCHER are used in the same meaning as defined therein.
The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be
interpreted as described in RFC 2119 [34].
[[[Editorial comments and questions about outstanding issues are
provided in triple brackets like this. These working comments should
be resolved and removed prior to final publication.]]]
2. Design Decisions
We have adopted the IMPP Model and Requirements documents [RFC2778,
RFC2779] as the starting point of our discussion. The two RFCs
contains some statements about presence information, which can be
regarded as a basic set of constraints for the format design. Also,
we took the minimalist approach to the design based on them. Starting
from the minimal model, only the features that are necessary to solve
particular problems were combined.
2.1. Minimal Model
This specification is based on the following minimal model and
requirements.
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(a) A presence data unit contains one or more PRESENCE TUPLES,
where a PRESENCE TUPLE consists of a STATUS, an optional
COMMUNICATION ADDRESS, and optional OTHER PRESENCE MARKUP.
(RFC2778:3)
(b) STATUS has at least the mutually-exclusive values OPEN and
CLOSED, which have meaning for the acceptance of INSTANT
MESSAGES, and may have meaning for other COMMUNICATION MEANS.
There may be other values of STATUS that do not imply anything
about INSTANT MESSAGE acceptance. These other values of STATUS
may be combined with OPEN and CLOSED or they may be mutually-
exclusive with those values. (RFC2778:3, RFC2779:4.4.1-3)
(c) STATUS may consist of single or multiple values. (RFC2778:2.4)
(d) There must be a means of extending the common presence format
to represent additional information not included in the common
format. The extension and registration mechanisms must be
defined for presence information schema, including new STATUS
conditions and new forms for OTHER PRESENCE MARKUP. (RFC2779:
3.1.4-5)
(e) The common presence format MUST include a means to uniquely
identify the PRESENTITY whose PRESENCE INFORMATION is reported.
(RFC2779:3.1.2)
(f) The common presence format must allow the source of the presence
data (i.e. presentity) to utilize some security mechanism (e.g.
digital signature or encryption) for the secure transportation
of the data. (RFC2779:5.2.1,5.3.1,5.3.3)
3. Overall Presence Information Data Structure
This memo defines a new content type and header fields for a MIME
entity containing CPIM presence data.
The CPIM presence format uses XML (eXtensible Markup Language, [XML])
as the syntactic framework for the presece data document because XML
is an excellent framework to contain structured data such as presence
information and inherently extensible. A new content type
"application/cpim-pidf+xml" is defined for the XML-encoded presence
documents.
The XML-encoded presence document MAY be enclosed by a MIME entity of
the content type "message/cpim", which is defined as the CPIM Message
Format [CPIM-MSG]. One of the cases for which the "message/cpim"
format is necessary is that the presence server gives the third party
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signature to the presence document with some additional data.
Note that the "application/cpim-pidf+xml" content itself can
optionally be signed or encrypted by the source of this presence data
using MIME security multiparts in conjunction with an appropriate
security scheme.
3.1. The 'application/cpim-pidf+xml' Content Type
The MIME body of the content type "application/cpim-pidf+xml"
includes the following information.
o Presentity URL: specifies the "pres" URL of the presentity.
o List of presence tuples
- Status: OPEN/CLOSED for Instant Messaging or status for
other communication means.
- Communication address: communication means and contact
address of this tuple. (optional)
- Relative priority: numerial value specifying the priority
of this communication address. (optional)
- Timestamp: timestamp of the change of this tuple.(optional)
- Human readable comment: free text memo about this tuple
(optional)
o Presentity human readable comment: free text memo about the
presentity (optional).
[[[ There were discussions on the IMPP mailing list about timestamp,
priority, and human readable comment. For the timestamp and priority,
it seems that we have reached a consensus. But, for human readable
comment, more discussions will be needed. ]]]
The content type "application/cpim-pidf+xml" MAY have a "charset"
parameter to indicate the character set and its encoding used in the
body. If no "charset" is specified, the application MUST treat the
body as "UTF-8" encoded.
3.2. Combining Multiple Presence Documents
If a presence service needs to combine multiple presence documents in
a single notification message, the MIME multipart entity is used.
The reason for using MIME multipart comes from an architectural
consideration such that each component presence document may come
from different sources and it might be secured with a MIME security
mechanism by the presence source.
For the purpose of combining multiple presence documents, the
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"multipart/mixed" content type MUST be used. Each part of the
multipart entity itself SHOULD be an "application/cpim-pidf+xml" type
MIME entity or a signed or encrypted MIME entity using the MIME
security multiparts in conjunction with an appropriate security
scheme.
Each multipart SHOULD contain a Presence-Data-ID header field whose
value is used by the watcher user agent to identify the
corresnponding part of the entire presence data of the particular
presentity.
4. XML-encoded Presence Data Format
This section defines an XML-encoded presence data format of the
content type application/cpim-pidf+xml for presence payloads. A
presence payload of this type is expected to be produced by the
presentity (the source of the presence information) and transported
to the watchers by the presence servers or gateways without any
interpretation or modification.
4.1. XML Format Definitions
An application/cpim-pidf+xml object is a well formed XML document.
4.1.1. The <presence> element
The root element of the 'application/cpim-pidf+xml' object is defined
as <presence>. This element contains one <presentity> element, one
or more <tuple> elements, and an optional <note> element.
The <presence> element SHOULD contain an 'xmlns' attribute to
indicate the namespace of the version of the presence document. The
presence document compliant to this specification MUST have the
namespace 'urn:ietf:params:cpim-presence:'.
4.1.2. The <presentity> element
The <presentity> element MUST have an 'id' attribute and has no
content. The value of the 'id' attribute is the 'pres' URL of the
publisher presentity of this presence information.
4.1.3. The <tuple> element
The <tuple> element is used to carry a piece of presence information
defined as PRESENCE TUPLE in RFC2778. Thus, it contains a mandatory
<status> element and optional <contact>, <note>, and <timestamp>
elements.
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The <tuple> element MUST contain an 'id' attribute which is used to
distinguish this tuple from other tuples of the same presentity. The
value of 'id' attribute MUST be unique in a single presentity.
The <contact> element is optional so as to allow a presentity to show
its status hiding its communication address or to allow tuples not
related to any communication means.
4.1.4. The <status> element
The <status> element contains one or more <value> elements. It can
have multiple status values at the same time.
4.1.5. The <value> element
The <value> element contains a CDATA value and has optional 'type'
and 'schema' attributes. The 'type' attribute indicates the type of
this value which restrict the range of the values in which the
content CDATA value varies. The 'schema' attribute is a URL
pointing to the definition of the type and its possible values, which
is usually a DTD.
If the type attribute does not appear, the application MUST
understand that the type is 'urn:ietf:params:cpim-presence:status-
type:basic', i.e. the 'basic' type whose possible values are either
"open" or "closed". As defined in RFC 2778, "open" and "closed"
stand for availability of receiving insatnt messages if the <tuple>
is for an instant messaging address. They also have meanings of
general availability for other communication means. But, this memo
does not specify them in detail.
Also, this memo does not specify other value types such as
'urn:ietf:params:cpim-presence:status-type:im'. However, the
'urn:ietf:params:cpim-presence:status-type:im' type will be defined
later in another specification document.
4.1.6. The <contact> element
The <contact> element contains a URL of the contact address. It
optionally has a 'priority' attribute, whose value means a relative
priority of this contact address over the others. The value of the
attribute MUST be an integer ranged from 0 to 255 and the smaller
integer means the higher priority. If the 'priority' attribute is
omitted, applications MUST understand that the contact address has
the lowest priority.
4.1.7. The <note> element
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The <note> element contains a CDATA value, which is usually used for
a human readable comment. A <note> element MAY appear as a child
element of <presence> and as that of the <tuple> element. In the
former case, the comment is about the presentity and, in the latter
case, the comment is regarding the particular tuple.
4.1.8. The <timestamp> element
The <timestamp> element contains a CDATA value which is a string
indicating the date and time of the status change of this tuple. The
value of this element MUST follow the IMPP datetime format
[DateTime].
4.2. Presence Information Extensibility
The presence information extensibility framework is based on XML
namespaces [XML-NS].
4.2.1. XML Namespaces Background
All elements and some attributes are associated with a "namespace",
which is in turn associated with a globally unique URI. Any
developer can introduce their own element names, avoiding conflict by
choosing an appropriate namespace URI.
Within the presence data, element or attribute names are associated
with a particular namespace by a namespace prefix, which is a leading
part of the name, followed by a colon (":"); e.g.
<prefix:element-name ...> ... </prefix:element-name>
Where, 'prefix' is the header name prefix, 'element-name' is a name
which is scoped by the namespace associated with 'prefix'. Note that
the choice of 'prefix' is quite arbitrary; it is the corresponding
URI that defines the naming scope. Two different prefixes associated
with the same namespace URI refer to the same namespace.
A default namespace can be declared for XML elements without a
namespace prefix. The default namespace does NOT apply to attribute
names, but interpretation of an unprefixed attribute can be
determined by the containing element.
A namespace is identified by a URI. In this usage, the URI is used
simply as a globally unique identifier, and there is no requirement
that it can be used to retrieve a web resource, or for any other
purpose. Any legal globally unique URI MAY be used to identify a
namespace. (By "globally unique", we mean constructed according to
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some set of rules so that it is reasonable to expect that nobody else
will use the same URI for a different purpose.)
For further details, see the XML namespace specification [XML-NS].
4.2.2. XML Namespaces In Presence Information
A URI used as a namespace identifier in presence information data
MUST be a full absolute-URI, per RFC 2396 [URI]. (Relative URIs and
URI- references containing fragment identifiers MUST NOT be used for
this purpose.)
The namespace URI for elements defined by this specification is a URN
[URN], using the namespace identifier 'ietf' defined by [URN-NS-IETF]
and extended by [URN-SUB-NS]:
urn:ietf:params:cpim-presence:
Thus, simple presence data might be thus:
<impp:presence xmlns:impp="urn:ietf:params:cpim-presence:">
<impp:presentity id="pres:shingo@jp.fujitsu.com">
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
</impp:presence>
or, using a default XML namespace:
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="mobile-phone">
<status>
<value>open</value>
</status>
<contact priority="9">tel:09012345678</contact>
</tuple>
</presence>
4.2.3. Handling Of Unrecognized Element Names
The default rule is that any element with an unrecognized name is
ignored (i.e. having an unrecognized namespace URI, or an
unrecognized local name within that namespace). This includes all of
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the element content, even if it appears to use recognized names.
It may be that some extensions must be understood in order for the
presence information to be properly understood. In such cases, the
element name is qualified with a mustUnderstand='YES' attribute,
which attribute name is associated with the CPIM presence namespace.
NOTE: a mustUnderstand='YES' attribute within an element that is
being ignored is itself ignored. The writer of nested mandatory-
to-understand information is responsible for ensuring that any
enclosing element is also labelled with a mustUnderstand='YES'
attribute, if necessary.
This specification defines elsewhere the elements within the
'urn:ietf:params:cpim-presence:' namespace that MUST be generated
and/or recognized in CPIM presence data. Processors MUST handle
these as described here, even if they do not carry a mustUnderstand
attribute.
If an agent receives presence information containing an unrecognized
element with a mustUnderstand='YES' attribute, it should treat the
entire presence information as unrecognized and not attempt to
process it.
4.3. Examples
4.3.1. Default Namespace And No Extensions
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com"/>
<tuple id="mobile-im">
<status>
<value>OPEN</value>
<value
type="urn:ietf:params:cpim-presence:status-type:im">BUSY</value>
<value
type="urn:example-com:cpim-status-type:location"
schema="http://www.example.com/impp/location.dtd">HOME</value>
</status>
<contact priority="2">im:shingo@mobilecarrier.ne.jp</contact>
<note>Don't Disturb Please!</note>
<timestamp>2001-10-27T16:49:29Z</timestamp>
</tuple>
<tuple id="email">
<status>
<value>OPEN</value>
</status>
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<contact priority="1">mailto:shingo@jp.fujitsu.com</contact>
</tuple>
<note>I'll be in Tokyo tomorrow</note>
</presence>
4.3.2. Example Presence Information Extensions
<impp:presence xmlns:impp="urn:ietf:params:cpim-presence:"
xmlns:myex="http://id.mycompany.com/cpim-presence/">
<impp:presentity id="pres:shingo@jp.fujitsu.com">
<myex:mytag>My extended presentity information</myex:mytag>
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<myex:mytupleelement>Extended value in tuple</myex:mytupleelement>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
<impp:tuple id="mobile-im">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<impp:contact priority="1">im:shingo@mobilecarrier.ne.jp</impp:contact>
</impp:tuple>
</impp:presence>
4.3.3. Example Mandatory To Understand Extensions
<impp:presence xmlns:impp="urn:iana:impp:presence:"
xmlns:myex="http://id.mycompany.com/cpim-presence/">
<impp:presentity id="pres:shingo@jp.fujitsu.com">
<myex:mytag>My extended presentity information</myex:mytag>
<impp:tuple id="mobile-phone">
<impp:status>
<impp:value>open</impp:value>
</impp:status>
<myex:complexExtension impp:mustUnderstand='YES'>
<myex:ex1 impp:mustUnderstand='YES'>val1</myex:ex1>
<myex:ex2>val2</myex:ex2>
</myex:mandatoryExtension>
<impp:contact priority="9">tel:09012345678</impp:contact>
</impp:tuple>
</impp:presence>
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Here, <myex:complexExtension>, <myex:ex1> must be understood, but
<myex:mytag> and <myex:ex2> may be ignored if they are not
recognized.
4.4. DTD
Data Type Definition of the application/cpim-pidf+xml format.
<!ENTITY % URL "CDATA">
<!ENTITY % URI "CDATA">
<!ENTITY % TUPLEID "CDATA">
<!ENTITY % DATETIME "CDATA">
<!ENTITY % VALUETYPE "CDATA">
<!ENTITY % PRIORITY "CDATA">
<!ENTITY % NOTE "CDATA">
<!ELEMENT presence (presentity,(tuple+),note?)>
<!ATTLIST presence
xmlns %URI; "urn:ietf:params:cpim-presence:"
>
<!ELEMENT presentity EMPTY>
<!ATTLIST presentity
id %URL; #REQUIRED
>
<!ELEMENT tuple (status,contact?,note?,timestamp?)>
<!ATTLIST tuple
id %TUPLEID; #REQUIRED
>
<!ELEMENT status (value+)>
<!ELEMENT value CDATA>
<!ATTLIST value
type %VALUETYPE;
"urn:ietf:params:cpim-presence:status-type:basic"
schema %URI; #IMPLIED
>
<!ELEMENT contact %URL;>
<!ATTLIST contact
priority %PRIORITY; #IMPLIED
>
<!ELEMENT note %NOTE;>
<!ELEMENT timestamp %DATETIME;>
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5. Wrapping 'application/cpim-pidf+xml' Data
[[[ A part of this section may contain what has not yet agreed upon
in the IMPP group. Futher discussions are needed. ]]]
As stated in Section 3, an 'application/cpim-pidf+xml' document MAY
be wrapped by a 'message/cpim' message [CPIM-MSG]. It MAY also be a
part of a MIME multipart entity. This section specifies how the
'application/cpim-pidf+xml' document can be packed in another MIME
entity.
5.1. When Used With 'message/cpim'
In order to use the CPIM Message Format, headers needed for this
usage must be defined [CPIM-MSG]. Among the headers defined by the
CPIM message format document, the following headers MAY be used to
convey the presence information. The default namespace and namespace
prefix implicitly defined are same as defined in the 'message/cpim'
specification document.
5.1.1. The 'From' header
The 'From' header contains the address (pres: URL) of the presentity
as the publisher of the contained presence information. Any
application compliant to this specification MUST recognize the 'From'
header.
This use of 'From' may be considered redundant in the presence of
<presentity> element in the presence document. This header is needed
when the presence server explicitly states the publisher regardless
of the content of presence documents.
5.1.2. The 'To' header
The 'To' header contains the address (pres: URL) of the watcher as
the target of the NOTIFY message containing this presence document.
Any application compliant to this specification MUST recognize the
'To' header.
5.1.3. The 'DateTime' header
The 'DateTime' header contains a character string of the format
defined as IMPP datetime format [DateTime]. This value indicates the
date and time at which the content part is created. The 'DateTime'
header MUST be present as a 'message/cpim' metadata header if the
message contains an 'application/cpim-pidf+xml' object. It MUST also
be recognized by any application compliant to this specification.
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5.1.4. The 'NS' header
The "NS" header is used to declare a local namespace prefix as
defined by [CPIM-MSG]. Any application compliant to this
specification MUST recognize the 'NS' header.
5.1.5. The 'Require' header
The "Require" header is used to specify a header or feature that must
be implemented by the receiver, as defined by [CPIM-MSG]. Any
application compliant to this specification MUST recognize the
'Require' header.
5.2. When Used With 'multipart/mixed'
When multiple presence documents are combined within a simple
notification message, the 'multipart/mixed' content type MUST be
used. Each multipart SHOULD contain a 'Presence-Data-ID' header
defined as follows.
5.2.1. The 'Presence-Data-ID' header
The 'Presence-Data-ID' header contains the label for the unit of
update. This header will be used for indicating the part is
replacement of the part which contained in previous NOTIFICATION with
same 'Presence-Data-ID' value.
5.3. Examples
The following example is the message/cpim object containing two
presence payload. It is supposed that the first block is published
by a PC and the second block is published by a mobile phone, and the
second block has caused the notification message conveying this
multipart content.
Content-Type: message/cpim
From: pres:shingo@jp.fujitsu.com
To: pres:suga@flab.fujitsu.co.jp
DateTime: 2001-06-01T08:35:44+09:00
Content-Type: multipart/mixed; boundary="PRESENCE-BLOCKS"
--PRESENCE-BLOCKS
Content-Type: application/cpim-pidf+xml
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Presence-Data-ID: part1
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="pc-im">
<status>
<value>OPEN</value>
<value
type="urn:ietf:params:cpim-presence:status-type:im">AWAY</value>
</status>
<contact priority="2">im:shingo@jp.fujitsu.com</contact>
<note>Boss Meeting</note>
</tuple>
<tuple id="email">
<status>
<value>OPEN</value>
</status>
<contact priority="1">mailto:shingo@jp.fujitsu.com</contact>
</tuple>
</presence>
--PRESENCE-BLOCKS
Content-Type: application/cpim-pidf+xml
Presence-Data-ID: part2
<presence xmlns="urn:ietf:params:cpim-presence:">
<presentity id="pres:shingo@jp.fujitsu.com">
<tuple id="mobile-phone">
<status>
<value>OPEN</value>
</status>
<contact priority="9">tel:09012345678</contact>
</tuple>
<tuple id="mobile-im">
<status>
<value>OPEN</value>
<value
type="urn:ietf:params:cpim-presence:status-type:location"
schema="http://www.example.com/impp/location.dtd">HOME</value>
</status>
<contact priority="2">im:shingo@mobilecarrier.ne.jp</contact>
</tuple>
</presence>
--PRESENCE-BLOCKS--
6. Security Considerations
The proposed format for conveying presence information is so designed
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that it could be adaptable in circumstances under various security
requirements.
As a typical case, a user publishing his/her presence information may
want to sign the data to prevent from being corrupted or tampered.
This will ensure the integrity of presence information in an end-to-
end manner. This proposal enables it by allowing MIME multipart
security framework, such as usage of the multipart/signed data type.
Another possible scenario is that of third party signing. If the
computing power of the terminal device of the publishing user is
restricted, the server side signing would be sometimes desirable to
enhance the level of security in distributing presence information.
This enables to prevent from so-called "the man in the middle"
attacks when the presence notifications are distributed through the
proxies or gateways.
7. IANA Considerations
[[[Will need a registration template per [URN-SUB-NS], for the URN
sub-namespace 'urn:ietf:params:cpim-presence:']]]
8. References
[CPIM] D. Crocker et al., "A Common Profile for Instant Messaging
(CPIM)", draft-ietf-impp-cpim-01.txt, Work in Progress. (Temporarily
Expired)
[CPIM-MSG] D. Atkins and G. Klyne, "Common Presence and Instant
Messaging Message Format", draft-ietf-impp-cpim-msgfmt-03.txt,
Work in Progress.
[RFC2778] M. Day, J. Rosenberg, H. Sugano, "A Model for Presence and
Instant Messaging", RFC 2778, February 2000.
[RFC2779] M. Day, S. Aggarwal, G. Mohr, and J. Vincent, "Instant
Messaging / Presence Protocol Requirements", RFC 2779, February 2000.
[XML] T. Bray, J. Paoli, C. Sperberg-McQueen and E. Maler,
"Extensible Markup Language (XML) 1.0 (Second Edition)",
W3C Recommendation, October 2000,
<http://www.w3.org/TR/2000/REC-xml-20001006>
[MIME] Multipurpose Internet Mail Extensions. See RFC 822, RFC 2045,
RFC 2046, RFC 2047, RFC 2048, and RFC 2049.
[DateTime] G. Klyne and C.Newman, "Date and Time on the Internet:
Sugano et al. [Page 16]
INTERNET DRAFT CPIM Presence Format October 2001
Timestamps", draft-ietf-impp-datetime-04.txt, Work in Progress.
[XML-NS] Tim Bray, Dave Hollander, and Andrew Layman "Namespaces in
XML", W3C recommendation: xml-names, 14 January 1999,
<http://www.w3.org/TR/REC-xml-names>
[URI] T. Berners-Lee, R.T.Fielding and L. Masinter, "Uniform
Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998.
[URN] R. Moats, "URN Syntax", RFC 2141, May 1997.
[URN-NS-IETF] R. Moats, "A URN Namespace for IETF Documents", RFC
2648, August 1999.
[URN-SUB-NS] M. Mealling, L. Masinter, T. Hardie and G. Klyne,
"An IETF URN Sub-namespace for Registered Protocol Parameters",
Internet-Draft draft-mealling-iana-urn-01, Work in Progress.
9. Author's Addresses
Hiroyasu Sugano
Fujitsu Laboratories Ltd.
64, Nishiwaki
Ohkubo-cho
Akashi 674
Japan
E-mail: sugano.h@jp.fujitsu.com
Shingo Fujimoto
Fujitsu Laboratories Ltd.
64, Nishiwaki
Ohkubo-cho
Akashi 674
Japan
E-mail: shingo_fujimoto@jp.fujitsu.com
Graham Klyne
Baltimore Technologies - Content Security Group,
1310 Waterside,
Arlington Business Park
Theale
Reading, RG7 4SA
United Kingdom.
Telephone: +44 118 903 8000
Facsimile: +44 118 903 9000
E-mail: GK@ACM.ORG
Sugano et al. [Page 17]
INTERNET DRAFT CPIM Presence Format October 2001
Adrian Bateman
VisionTech Limited
Colton, Staffordshire, WS15 3LD
United Kingdom
E-mail: bateman@acm.org
10. Full Copyright Statement
Copyright (C) The Internet Society (2001). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Sugano et al. [Page 18]