SIMPLE WG M. Lonnfors
Internet-Draft K. Kiss
Expires: February 1, 2007 Nokia
July 31, 2006
Session Initiation Protocol (SIP) User Agent Capability Extension to
Presence Information Data Format (PIDF)
draft-ietf-simple-prescaps-ext-07
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Copyright (C) The Internet Society (2006).
Abstract
Presence Information Data Format (PIDF) defines a common presence
data format for Common Profile for Presence (CPP) compliant Presence
protocols. This memo defines an extension to represent SIP User
Agent capabilities in the Presence Information Document Format (PIDF)
compliant presence documents.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Extension for "Indicating User Agent Capabilities in the
Session Initiation Protocol (SIP)" in PIDF documents . . . . . 5
3.1. Overview of operation . . . . . . . . . . . . . . . . . . 5
3.2. Service capabilities . . . . . . . . . . . . . . . . . . . 6
3.2.1. <servcaps> element . . . . . . . . . . . . . . . . . . 6
3.2.2. <audio> element . . . . . . . . . . . . . . . . . . . 6
3.2.3. <application> element . . . . . . . . . . . . . . . . 6
3.2.4. <data> element . . . . . . . . . . . . . . . . . . . . 7
3.2.5. <control> element . . . . . . . . . . . . . . . . . . 7
3.2.6. <video> element . . . . . . . . . . . . . . . . . . . 7
3.2.7. <text> element . . . . . . . . . . . . . . . . . . . . 7
3.2.8. <message> element . . . . . . . . . . . . . . . . . . 7
3.2.9. <type> element . . . . . . . . . . . . . . . . . . . . 8
3.2.10. <automata> element . . . . . . . . . . . . . . . . . . 8
3.2.11. <class> element . . . . . . . . . . . . . . . . . . . 8
3.2.12. <duplex> element . . . . . . . . . . . . . . . . . . . 9
3.2.13. <description> element . . . . . . . . . . . . . . . . 9
3.2.14. <event-packages> element . . . . . . . . . . . . . . . 9
3.2.15. <priority> element . . . . . . . . . . . . . . . . . . 10
3.2.16. <methods> element . . . . . . . . . . . . . . . . . . 11
3.2.17. <extensions> element . . . . . . . . . . . . . . . . . 11
3.2.18. <schemes> element . . . . . . . . . . . . . . . . . . 12
3.2.19. <actor> element . . . . . . . . . . . . . . . . . . . 12
3.2.20. <isfocus> element . . . . . . . . . . . . . . . . . . 13
3.2.21. <languages> element . . . . . . . . . . . . . . . . . 13
3.3. Device capabilities . . . . . . . . . . . . . . . . . . . 13
3.3.1. <devcaps> element . . . . . . . . . . . . . . . . . . 14
3.3.2. <mobility> element . . . . . . . . . . . . . . . . . . 14
3.3.3. <priority> element . . . . . . . . . . . . . . . . . . 15
3.3.4. <description> element . . . . . . . . . . . . . . . . 15
4. Usage guidelines . . . . . . . . . . . . . . . . . . . . . . . 16
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. XML schema definitions . . . . . . . . . . . . . . . . . . . . 17
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
7.1. URN sub-namespace registration for
'urn:ietf:params:xml:ns:pidf:caps' . . . . . . . . . . . . 26
8. Security Considerations . . . . . . . . . . . . . . . . . . . 26
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.1. Normative references . . . . . . . . . . . . . . . . . . . 27
10.2. Informative references . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 29
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Intellectual Property and Copyright Statements . . . . . . . . . . 30
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1. Introduction
Common Profile for Presence (CPP) [1] and Common Profile for Instant
Messaging (CPIM) [12] define common operations and formats which all
presence and instant messaging services must agree upon so that basic
interoperability would be possible. The actual base format for the
presence is defined in the Presence Information Document Format
(PIDF) [4]. The PIDF has been designed to reduce the need for
gatewaying and to allow end-to-end security of presence data. It has
taken a very minimalistic approach to support such operations. In
order to make the PIDF usable by different presence applications,
these applications usually must extend the basic PIDF by standard XML
mechanisms as defined in PIDF [4].
The aim of this memo is to introduce a SIP specific extension
mechanism to the PIDF that conveys the same SIP media feature tags as
described in RFC3840 [5]. With this extension presence applications
based on SIP can have richer and more usable presence data compared
to the baseline PIDF.
1.1. Motivation
The PIDF [4] defines a <contact> element which may appear once inside
every <tuple> element. The content of the <contact> element encodes
the CONTACT ADDRESS and CONTACT MEANS as defined in RFC2778 [3]. The
<contact> element is defined to be a URI of any scheme. In some
implementations the URI scheme can uniquely identify the service the
tuple intends to describe (e.g. im: URI scheme usually represents
Instant Messaging service). However, this may not be the case in all
implementations. For example in SIP, a SIP URI scheme can represent
different kinds of services. A SIP URI scheme can be used to contact
voice services, video services, or messaging services. If it is not
known by other means, it might be hard for applications processing
the presence information document containing only a SIP URI contact
addresses to know what particular service the tuple intends to
describe. Also watchers receiving presence information would
probably benefit for getting more descriptive information about what
particular communication means or services are supported by the
presentity.
RFC3840 [5] defines a set of extensions which allow callees to
express preferences about request handling in SIP servers. The same
information can provide value also to presence watchers so that they
can make more rational decisions on how a presentity should be
contacted if a presence document contained similar information.
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1.2. Scope
This document defines extensions to the PIDF which enables presence
implementations based on SIP to utilize similar information in a
presence information document as what RFC3840 [5] defines.
This extension does not replace media negotiation mechanisms defined
for SIP (e.g. SDP [13]). This extension is only aimed for
presentities to give watchers hints about the presentity's
preferences, willingness and capabilities to communicate before
watchers initiate a communication with the presentity.
2. Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119. [2].
This memo makes use of the vocabulary defined in RFC2778 [3], and in
RFC3863 [4].
3. Extension for "Indicating User Agent Capabilities in the Session
Initiation Protocol (SIP)" in PIDF documents
This section presents all extension documents, their elements, their
values, and semantics. This section also describes how this
extension can be further extended.
This extension is intended to be used within a PIDF [4] and that
particular usage is described here. This extension may also be used
with other XML documents if appropriate.
3.1. Overview of operation
This document defines how the features presented in RFC3840 [5] can
be provided as a part of presence data. Additionally, this memo
includes the "type" feature tag [6], "message" media type feature tag
[14] and the "language" feature tag [7] definitions. Bringing these
features in the PIDF means mapping them to an XML formatted
structure.
The presence data model [10] defines presence data consisting of
three types of data elements: person, service, and device. This memo
follows this model so that one XML document is defined to describe
device capabilities and another one to describe service capabilities.
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The namespace URIs for elements defined by this document are URNs
using the namespace identifier 'ietf' defined by RFC2648 [8] and
extended by RFC3688 [9].
When these extension namespaces are congregated with the PIDF
document, the combined document MUST follow the same general
formatting rules as specified in Section 4.1 of the RFC3863 [4].
3.2. Service capabilities
Elements belonging to service capabilities are used to describe
dynamic characteristics of a service. These capabilities are
enclosed within the <servcaps> element which SHOULD be located in
PIDF document as a child element of urn:ietf:params:xml:ns:pidf
namespace <tuple> [4] element.
Namespace identifier for these elements is:
urn:ietf:params:xml:ns:pidf:caps
3.2.1. <servcaps> element
The root element of service capabilities is <servcaps>. The root
element has to be always present. This element can contain following
elements: <audio>, <application>, <control>, <video>, <text>,
<message>, <type>, <automata>, <class>, <duplex>, <description>,
<event-packages>, <priority>, <methods>, <extensions>, <schemes>,
<actor>, <isfocus>, and <languages> followed by any number of
optional extension elements from other namespaces.
A <servcaps> element does not have any attributes.
3.2.2. <audio> element
The <audio> element indicates that the service supports audio as a
streaming media type as defined in RFC3840 [5].
The <audio> element is a boolean type and does not have any
attributes. The value 'true' indicates that service supports audio
media type and the value 'false' indicates that service does not
support audio media type.
3.2.3. <application> element
The <application> element indicates that the service supports
application as a streaming media type as defined in RFC3840 [5].
The <application> element is a boolean type and does not have any
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attributes. The value 'true' indicates that service supports
application media type and the value 'false' indicates that service
does not support application media type.
3.2.4. <data> element
The <data> element indicates that the service supports data as a
streaming media type as defined in RFC3840 [5].
The <data> element is a boolean type and does not have any
attributes. The value 'true' indicates that service supports data
media type and the value 'false' indicates that service does not
support data media type.
3.2.5. <control> element
The <control> element indicates that the service supports control as
a streaming media type as defined in RFC3840 [5].
The <control> element is a boolean type and does not have any
attributes. The value 'true' indicates that service supports control
media type and the value 'false' indicates that service does not
support control media type.
3.2.6. <video> element
The <video> element indicates that the service supports video as a
streaming media type as defined in RFC3840 [5].
The <video> element is a boolean type and does not have any
attributes. The value 'true' indicates that service supports video
media type and the value 'false' indicates that service does not
support video media type.
3.2.7. <text> element
The <text> element indicates that the service supports text as a
streaming media type as defined in RFC3840 [5].
The <text> element is a boolean type and does not have any
attributes. the value 'true' indicates that service supports text
media type and the value 'false' indicates that service does not
support text media type.
3.2.8. <message> element
The <message> element indicates that the service supports message as
a streaming media type as defined in [14].
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The <message> element is a boolean type and does not have any
attributes. The value 'true' indicates that service supports message
media type and the value 'false' indicates that service does not
support message media type.
3.2.9. <type> element
The <type> element indicates a MIME media content type (i.e. that
appears in a 'Content-type:' header of the corresponding MIME-
formatted data) as defined in RFC2913 [6].
The <type> element is a string type and does not have any attributes.
It MUST be a string of the form "type/subtype", where 'type' and
'subtype' are defined by the MIME specification [11]. Only lower-
case letters SHOULD be used.
3.2.10. <automata> element
The <automata> element indicates whether the service represents an
automata (such as a voicemail server, conference server, IVR, or
recording device) or a human as defined in RFC3840 [5].
The <automata> element is a boolean type and does not have any
attributes. The value 'true' indicates that the service represents
an automata and the value 'false' indicates that it represents a
human.
3.2.11. <class> element
The <class> element indicates the setting, business or personal, in
which a communications service is used as defined in RFC3840 [5].
The <class> element can contain two elements: <supported> and
<notsupported>. All classes that are supported by the service are
listed under <supported> element and all classes that are not
supported by the service are listed under <notsupported> element.
<supported> and <notsupported> elements can contain <business> and
<personal> elements followed by any number of optional extension
elements from other namespaces. The semantics of business and
personal are defined in RFC3840 [5] as:
o <business>: The service is used for business communications.
o <personal>: The service is used for personal communications.
Any value that is registered with IANA for the SIP Media Feature Tag
Registration Tree as a sip.class media feature tag can be used as a
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value of an extension element. If the appropriate value is not
registered it SHOULD be registed as defined in RFC3840 [5].
3.2.12. <duplex> element
The <duplex> element lists whether a communications service can
simultaneously send and receive media ("full"), alternate between
sending and receiving ("half"), only receive ("receive-only") or only
send ("send-only") as defined in RFC3840 [5].
The <duplex> element can contain two elements: <supported> and
<notsupported>. All duplex modes that are supported by the service
are listed under <supported> element and all duplex modes that are
not supported by the service are listed under <notsupported> element.
<supported> and <notsupported> elements can contain <full>, <half>,
<receive-only> and <send-only> elements followed by any number of
optional extension elements from other namespaces. The semantics of
these elements are defined in RFC3840 [5] as:
o <full>: The service can simultaneously send and receive media.
o <half>: The service can alternate between sending and receiving
media.
o <receive-only>: The service can only receive media.
o <send-only>: The service can only send media.
Any value that is registered with IANA for the SIP Media Feature Tag
Registration Tree as a sip.class media feature tag can be used as a
value of an extension element. If the appropriate value is not
registered it SHOULD be registed as defined in RFC3840 [5].
3.2.13. <description> element
The <description> element provides a textual description of the
service as defined in RFC3840 [5].
The <description> element is of string type and does not have any
attributes.
3.2.14. <event-packages> element
The <event-packages> element lists the event packages supported by a
service.
The <event-packages> element can contain two elements: <supported>
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and <notsupported>. All event packages that are supported by the
service are listed under <supported> element and all event packages
that are not supported by the service are listed under <notsupported>
element.
<supported> and <notsupported> elements can contain <presence>,
<message-summary>, <reg>, <refer>, <winfo>, <spirits-user-prof>,
<spirits-user-prof>, <spirits-INDPs>, and <Siemens-RTP-Stats>
followed by any number of optional extension elements from other
namespaces.
Any value that is registered with IANA for the SIP Event types
namespace registry can be used as a value of an extension element.
3.2.15. <priority> element
The <priority> element indicates the call priorities the service is
willing to handle.
The <priority> element can contain two elements: <supported> and
<notsupported>. All priority values that are supported by the
service are listed under <supported> element and all priority values
that are not supported by the service are listed under <notsupported>
element.
The <supported> and <notsupported> elements can contain any number of
<lowerthan>, <higherthan>, <equals> and <range> elements followed by
any number of optional extension elements from other namespaces.
3.2.15.1. <lowerthan> element
The <lowerthan> element has a single attribute called "maxvalue".
The "maxvalue" attribute is used to give the highest priority value
that the service is willing to support. All values equal and below
that value are supported.
3.2.15.2. <higherthan> element
The <higherthan> element has a single attribute called "minvalue".
The "minvalue" attribute is used to give the lowest priority value
that the service is willing to support. All values equal and above
that value are supported.
3.2.15.3. <equals> element
The <equals> element is used to indicate the exact priority value
that the service is willing to handle. The <equals> element has a
single attribute called "value". The "value" attribute is used to
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indicate the exact supported priority value.
3.2.15.4. <range> element
The <range> element is used to indicate the priority range that the
service is willing to handle. The <range> element has two attributes
called "min" and "max". Value of the "min" attribute indicates
lowest priority value supported by the service and the value of the
"max" attribute indicates the highest priority value supported by the
service.
3.2.16. <methods> element
The <methods> element indicates the SIP methods supported by a
service. In this case, "supported" means that the service can
receive requests with this method. In that sense, it has the same
connotation as the Allow header field as defined in RFC3840 [5].
The <methods> element can contain two elements: <supported> and
<notsupported>. All methods that are supported by the service are
listed under <supported> element and all methods that are not
supported by the service are listed under <notsupported> element.
The <supported> and <notsupported> elements can contain <ACK>, <BYE>,
<CANCEL>, <INFO>, <INVITE>, <MESSAGE>, <NOTIFY>, <OPTIONS>, <PRACK>,
<PUBLISH>, <REFER>, <REGISTER>, <SUBSCRIBE>, and <UPDATE> elements
followed by any number of optional extension elements from other
namespaces.
Any value that is registered with IANA for the SIP methods namespace
registry can be used as a value of an extension element.
3.2.17. <extensions> element
The <extensions> element is a list of SIP extensions (each of which
is defined by an option-tag registered with IANA) that are understood
by the service. Understood, in this context, means that the option
tag would be included in a Supported header field in a request as
defined in RFC3840 [5].
The <extensions> element can contain two elements: <supported> and
<notsupported>. All extensions that are supported by the service are
listed under <supported> element and all extensions that are not
supported by the service are listed under <notsupported> element.
The <supported> and <notsupported> elements can contain <rel100>,
<join>, <path>, <precondition>, <pref>, <privacy>, <replaces>,
<histinfo> and <sec-agree> elements followed by any number of
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optional extension elements from other namespaces.
Any value that is defined in IANA SIP parameters registry option tags
table can be used as a value of an extension element.
3.2.18. <schemes> element
The <schemes> element provides the set of URI schemes that are
supported by a service. Supported implies, for example, that the
service would know how to handle a URI of that scheme in the Contact
header field of a redirect response as defined in [5].
The <schemes> element can contain two elements: <supported> and
<notsupported>. All schemes that are supported by the service are
listed under <supported> element and all schemes that are not
supported by the service are listed under <notsupported> element.
<supported> and <notsupported> elements can contain any number of <s>
elements which can be used to describe individual schemes supported
by the service.
3.2.18.1. <s> element
The <s> element is of string type and it is used to describe
individual scheme supported by the service. Values that can be used
here are scheme names that are registered to IANA URI scheme
registry.
3.2.19. <actor> element
The <actor> element indicates the type of entity that is available at
this URI as defined in RFC3840 [5].
The <actor> element can contain two elements: <supported> and
<notsupported>. All actor types that are supported by the service
are listed under <supported> element and all actor types that are not
supported by the service are listed under <notsupported> element.
The <supported> and <notsupported> elements can contain <principal>,
<attendant>, <msg-taker>, and <information> elements followed by any
number of optional extension elements from other namespaces.
The semantics of these elements are defined in RFC3840 [5] as:
o <principal>: The service provides communication with the principal
that is associated with the service. Often this will be a
specific human being, but it can be an automata (for example, when
calling a voice portal).
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o <attendant>: The service provides communication with an automata
or person that will act as an intermediary in contacting the
principal associated with the service, or a substitute.
o <msg-taker>: The service provides communication with an automata
or person that will take messages and deliver them to the
principal.
o <information>: The service provides communication with an automata
or person that will provide information about the principal.
Any value that is registered with IANA for the SIP Media Feature Tag
Registration Tree as a sip.class media feature tag can be used as a
value of an extension element. If the appropriate value is not
registered it SHOULD be registed as defined in RFC3840 [5].
3.2.20. <isfocus> element
The <isfocus> element indicates that the service is a conference
server, also known as a focus as defined in RFC3840 [5].
The <isfocus> element is of boolean type and does not have any
attributes.
3.2.21. <languages> element
The <languages> element indicates the ability to display particular
human languages as defined in RFC2987 [7].
The <languages> element can contain two elements: <supported> and
<notsupported>. All languages that are supported by the service are
listed under <supported> element and all languages that are not
supported by the service are listed under <notsupported> element.
<supported> and <notsupported> elements can contain any number of <l>
elements which can be used to describe individual languages supported
by the service.
3.2.21.1. <l> element
The <l> element is of string type and it is used to describe
individual language supported by the service. Values that can be
used here are language names that are registered to IANA as per
RFC2987 [7].
3.3. Device capabilities
Elements belonging to service capabilities are used to describe
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dynamic characteristics of a service. These capabilities are
enclosed within the <devcaps> element which SHOULD be located in the
PIDF document as a child element of
urn:ietf:params:xml:ns:pidf:data-model namespace <device> element
[10].
Namespace identifier for these elements is urn:
ietf:params:xml:ns:pidf:caps
3.3.1. <devcaps> element
The root element of device capabilities is <devcaps>. The root
element has to be always present. This element can contain following
elements: <mobility>, <priority>, and <description> followed by any
number of optional extension elements from other namespaces.
A <devcaps> element does not have any attributes.
3.3.2. <mobility> element
The <mobility> element indicates whether the device is fixed (meaning
that it is associated with a fixed point of contact with the
network), or mobile (meaning that it is not associated with a fixed
point of contact). Note that cordless phones are fixed, not mobile,
based on this definition as defined in RFC3840 [5].
The <mobility> element can contain two elements: <supported> and
<notsupported>. All mobility modes that are supported by the device
are listed under <supported> element and all mobility modes that are
not supported by the device are listed under <notsupported> element.
The <supported> and <notsupported> elements can contain <fixed> and
<mobile> elements followed by any number of optional extension
elements from other namespaces.
The semantics of these elements are defined in RFC3840 [5] as:
o <fixed>: The device is stationary.
o <mobile>: The device can move around with the user.
Any value that is register to IANA to SIP Media Feature Tag
Registration Tree as sip.mobility media feature tag can be used as a
value of an extension element. If the appropriate value is not
registered it SHOULD be registed as defined in RFC3840 [5].
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3.3.3. <priority> element
The <priority> element indicates the call priorities the device is
willing to handle.
The <priority> element can contain two elements: <supported> and
<notsupported>. All priority values that are supported by the device
are listed under <supported> element and all priority values that are
not supported by the device are listed under <notsupported> element.
The <supported> and <notsupported> elements can contain any number of
<lowerthan>, <higherthan>, <equals> and <range> elements followed by
any number of optional extension elements from other namespaces.
3.3.3.1. <lowerthan> element
The <lowerthan> element has a single attribute called "maxvalue".
The "maxvalue" attribute is used to give the highest priority value
that the device is willing to support. All values equal and below
that value are supported.
3.3.3.2. <higherthan> element
The <higherthan> element has a single attribute called "minvalue".
The "minvalue" attribute is used to give the lowest priority value
that the device is willing to support. All values equal and above
that value are supported.
3.3.3.3. <equals> element
The <equals> element is used to indicate the exact priority value
that the device is willing to handle. The <equals> element has a
single attribute called "value". Value of the "value" attribute is
used to indicate the exact supported priority value.
3.3.3.4. <range> element
The <range> element is used to indicate the priority range that the
device is willing to handle. The <range> element has two attributes
called "min" and "max". Value of the "min" attribute indicates
lowest priority value supported by the device and the value of the
"max" attribute indicates the highest priority value supported by the
device.
3.3.4. <description> element
The <description> element provides a textual description of the
device as defined in RFC3840 [5].
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The <description> element is of string type and does not have any
attributes.
4. Usage guidelines
In RFC3840 [5] it is recommended that a UA provides complete
information in its contact predicate. However, it may be that
presentity is not willing to publish presence information which would
be consistent with actual device or service capabilities (e.g.
presentity may not want to indicate that he/she supports voice when
the service actually is able to support it). Also authorization
rules or policies in presence server may limit or modify the
published presence information in a way that all published presence
information may not end up to all possible watchers.
It is RECOMMENTED that Presence User Agents (PUAs) using this
extension provide as complete presence information as they can. If
the PUA is publishing sensitive information using this extension, it
SHOULD obtain a permission from a user. PUAs can indicate all the
explicitly supported capabilities using the <supported> element and
all the explicitly not supported capabilities using the
<notsupported> element, where appropriate.
However, it is not mandated that this presence information should be
consistent with actual device capabilities. Also, watchers should
not expect that the presence information represented by this
extension fully represents the actual presentity's device
capabilities.
5. Examples
<?xml version="1.0" encoding="UTF-8"?>
<presence xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:caps="urn:ietf:params:xml:ns:pidf:caps"
xmlns:mod="urn:ietf:params:xml:ns:pidf:data-model"
entity="pres:someone@example.com">
<tuple id="joi9877866786ua9">
<status>
<basic>open</basic>
</status>
<caps:servcaps>
<caps:audio>true</caps:audio>
<caps:description>
Example service
</caps:description>
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<caps:duplex>
<caps:supported>
<caps:full/>
</caps:supported>
</caps:duplex>
<caps:message>true</caps:message>
<caps:methods>
<caps:supported>
<caps:ACK/>
<caps:BYE/>
<caps:INVITE/>
</caps:supported>
</caps:methods>
<caps:priority>
<caps:supported>
<caps:lowerthan maxvalue="10"/>
</caps:supported>
</caps:priority>
<caps:schemes>
<caps:supported>
<caps:s>sip</caps:s>
</caps:supported>
</caps:schemes>
<caps:video>false</caps:video>
</caps:servcaps>
<contact>sip:someone@example.com</contact>
</tuple>
<mod:device id="hgt67">
<caps:devcaps>
<caps:mobility>
<caps:supported>
<caps:mobile/>
</caps:supported>
</caps:mobility>
</caps:devcaps>
<mod:deviceID
>urn:uuid:d27459b7-8213-4395-aa77-ed859a3e5b3a</mod:deviceID>
</mod:device>
</presence>
6. XML schema definitions
This section gives the XML schema definitions for the extensions
defined in this document. Namespace identifier for this schema is
urn:ietf:params:xml:ns:pidf:caps.
<?xml version="1.0" encoding="UTF-8"?>
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<xs:schema xmlns:tns="urn:ietf:params:xml:ns:pidf:caps"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="urn:ietf:params:xml:ns:pidf:caps"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<!-- This import brings in the XML language
attribute xml:lang-->
<xs:import namespace="http://www.w3.org/XML/1998/namespace"
schemaLocation="http://www.w3.org/2001/xml.xsd"/>
<!-- ROOT -->
<xs:element name="servcaps" type="tns:servcapstype"/>
<xs:complexType name="servcapstype">
<xs:sequence>
<xs:element name="actor" type="tns:actortype"
minOccurs="0"/>
<xs:element name="application" type="tns:applicationtype"
minOccurs="0"/>
<xs:element name="audio" type="tns:audiotype" minOccurs="0"/>
<xs:element name="automata" type="tns:automatatype"
minOccurs="0"/>
<xs:element name="class" type="tns:classtype"
minOccurs="0"/>
<xs:element name="control" type="tns:controltype"
minOccurs="0"/>
<xs:element name="data" type="tns:datatype"
minOccurs="0"/>
<xs:element name="description" type="tns:descriptiontype"
minOccurs="0"/>
<xs:element name="duplex" type="tns:duplextype"
minOccurs="0"/>
<xs:element name="event-packages" type="tns:event-packagestype"
minOccurs="0"/>
<xs:element name="extensions" type="tns:extensionstype"
minOccurs="0"/>
<xs:element name="isfocus" type="tns:isfocustype"
minOccurs="0"/>
<xs:element name="message" type="tns:messagetype"
minOccurs="0"/>
<xs:element name="methods" type="tns:methodstype"
minOccurs="0"/>
<xs:element name="languages" type="tns:languagestype"
minOccurs="0"/>
<xs:element name="priority" type="tns:prioritytype"
minOccurs="0"/>
<xs:element name="schemes" type="tns:schemestype"
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minOccurs="0"/>
<xs:element name="text" type="tns:texttype"
minOccurs="0"/>
<xs:element name="type" type="tns:typetype"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="video" type="tns:videotype"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:element name="devcaps" type="tns:devcaps"/>
<xs:complexType name="devcaps">
<xs:sequence>
<xs:element name="description" type="tns:descriptiontype"
minOccurs="0"/>
<xs:element name="mobility" type="tns:mobilitytype"
minOccurs="0"/>
<xs:element name="priority" type="tns:prioritytype"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- AUDIO -->
<xs:simpleType name="audiotype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- APPLICATION -->
<xs:simpleType name="applicationtype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- DATA -->
<xs:simpleType name="datatype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- CONTROL -->
<xs:simpleType name="controltype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- VIDEO -->
<xs:simpleType name="videotype">
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<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- TEXT -->
<xs:simpleType name="texttype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- MESSAGE -->
<xs:simpleType name="messagetype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- TYPE -->
<xs:simpleType name="typetype">
<xs:restriction base="xs:string"/>
</xs:simpleType>
<!-- AUTOMATA -->
<xs:simpleType name="automatatype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- CLASS -->
<xs:complexType name="classtype">
<xs:sequence>
<xs:element name="supported" type="tns:classtypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:classtypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="classtypes">
<xs:sequence>
<xs:element name="business" type="xs:string"
minOccurs="0"/>
<xs:element name="personal" type="xs:string"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- DUPLEX -->
<xs:complexType name="duplextype">
<xs:sequence>
<xs:element name="supported" type="tns:duplextypes"
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minOccurs="0"/>
<xs:element name="notsupported" type="tns:duplextypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="duplextypes">
<xs:sequence>
<xs:element name="full" type="xs:string"
minOccurs="0"/>
<xs:element name="half" type="xs:string"
minOccurs="0"/>
<xs:element name="receive-only" type="xs:string"
minOccurs="0"/>
<xs:element name="send-only" type="xs:string"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- DESCRIPTION -->
<xs:simpleType name="descriptiontype">
<xs:restriction base="xs:string"/>
</xs:simpleType>
<!-- EVENT-PACKAGES -->
<xs:complexType name="event-packagestype">
<xs:sequence>
<xs:element name="supported" type="tns:eventtypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:eventtypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="eventtypes">
<xs:sequence>
<xs:element name="message-summary" type="xs:string"
minOccurs="0"/>
<xs:element name="presence" type="xs:string"
minOccurs="0"/>
<xs:element name="refer" type="xs:string"
minOccurs="0"/>
<xs:element name="reg" type="xs:string"
minOccurs="0"/>
<xs:element name="Siemens-RTP-Stats"
type="xs:string" minOccurs="0"/>
<xs:element name="spirits-INDPs"
type="xs:string" minOccurs="0"/>
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<xs:element name="spirits-user-prof"
type="xs:string" minOccurs="0"/>
<xs:element name="winfo" type="xs:string"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- PRIORITY -->
<xs:complexType name="prioritytype">
<xs:sequence>
<xs:element name="supported" type="tns:prioritytypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:prioritytypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="prioritytypes">
<xs:sequence>
<xs:element name="equals" type="tns:equalstype"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="higherhan" type="tns:higherthantype"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="lowerthan" type="tns:lowerthantype"
minOccurs="0" maxOccurs="unbounded"/>
<xs:element name="range" type="tns:rangetype"
minOccurs="0" maxOccurs="unbounded"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="lowerthantype">
<xs:attribute name="maxvalue" type="xs:integer"
use="required"/>
</xs:complexType>
<xs:complexType name="higherthantype">
<xs:attribute name="minvalue" type="xs:integer"
use="required"/>
</xs:complexType>
<xs:complexType name="equalstype">
<xs:attribute name="value" type="xs:integer"
use="required"/>
</xs:complexType>
<xs:complexType name="rangetype">
<xs:attribute name="minvalue" type="xs:integer"
use="required"/>
<xs:attribute name="maxvalue" type="xs:integer"
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use="required"/>
</xs:complexType>
<!-- METHODS -->
<xs:complexType name="methodstype">
<xs:sequence>
<xs:element name="supported" type="tns:methodtypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:methodtypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="methodtypes">
<xs:sequence>
<xs:element name="ACK" type="xs:string" minOccurs="0"/>
<xs:element name="BYE" type="xs:string" minOccurs="0"/>
<xs:element name="CANCEL" type="xs:string" minOccurs="0"/>
<xs:element name="INFO" type="xs:string" minOccurs="0"/>
<xs:element name="INVITE" type="xs:string" minOccurs="0"/>
<xs:element name="MESSAGE" type="xs:string" minOccurs="0"/>
<xs:element name="NOTIFY" type="xs:string" minOccurs="0"/>
<xs:element name="OPTIONS" type="xs:string" minOccurs="0"/>
<xs:element name="PRACK" type="xs:string" minOccurs="0"/>
<xs:element name="PUBLISH" type="xs:string" minOccurs="0"/>
<xs:element name="REFER" type="xs:string" minOccurs="0"/>
<xs:element name="REGISTER" type="xs:string" minOccurs="0"/>
<xs:element name="SUBSCRIBE" type="xs:string" minOccurs="0"/>
<xs:element name="UPDATE" type="xs:string" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- EXTENSIONS -->
<xs:complexType name="extensionstype">
<xs:sequence>
<xs:element name="supported" type="tns:extensiontypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:extensiontypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="extensiontypes">
<xs:sequence>
<xs:element name="join" type="xs:string" minOccurs="0"/>
<xs:element name="path" type="xs:string" minOccurs="0"/>
<xs:element name="precondition" type="xs:string" minOccurs="0"/>
<xs:element name="pref" type="xs:string" minOccurs="0"/>
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<xs:element name="privacy" type="xs:string" minOccurs="0"/>
<xs:element name="rel100" type="xs:string" minOccurs="0"/>
<xs:element name="replaces" type="xs:string" minOccurs="0"/>
<xs:element name="sec-agree" type="xs:string" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<!-- SCHEMES -->
<xs:complexType name="schemestype">
<xs:sequence>
<xs:element name="supported" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element name="s" type="xs:string" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="notsupported" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element name="s" type="xs:string" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
<!-- ACTOR -->
<xs:complexType name="actortype">
<xs:sequence>
<xs:element name="supported" type="tns:actortypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:actortypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="actortypes">
<xs:sequence>
<xs:element name="attendant" type="xs:string" minOccurs="0"/>
<xs:element name="information" type="xs:string" minOccurs="0"/>
<xs:element name="msg-taker" type="xs:string" minOccurs="0"/>
<xs:element name="principal" type="xs:string" minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
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<!-- ISFOCUS -->
<xs:simpleType name="isfocustype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- LANGUAGES -->
<xs:complexType name="languagestype">
<xs:sequence>
<xs:element name="supported" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element name="l" type="xs:string" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="notsupported" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element name="l" type="xs:string" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
<!-- MOBILITY -->
<xs:complexType name="mobilitytype">
<xs:sequence>
<xs:element name="supported" type="tns:mobilitytypes"
minOccurs="0"/>
<xs:element name="notsupported" type="tns:mobilitytypes"
minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="mobilitytypes">
<xs:sequence>
<xs:element name="fixed" type="xs:string"
minOccurs="0"/>
<xs:element name="mobile" type="xs:string"
minOccurs="0"/>
<xs:any namespace="##other" processContents="lax" minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:schema>
Figure 2
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7. IANA Considerations
This memo calls for IANA to register one new XML namespace URNs as
defined in RFC3688 [9].
7.1. URN sub-namespace registration for
'urn:ietf:params:xml:ns:pidf:caps'
URI:
urn:ietf:params:xml:ns:pidf:caps
Description:
This is the XML namespace for XML elements defined by [[[RFCXXXX]]]
to describe service and device capabilities in application/pidf+xml
content type.
Registrant Contact:
IETF, SIMPLE working group, <simple@ietf.org>
Mikko Lonnfors, <mikko.lonnfors@nokia.com>
XML:
BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml
<head>
<meta http-equiv="content-type"
content="text/html;charset=iso-8859-1"/>
<title>Namespace for PIDF user agent capability
extension</title>
</head>
<body>
<h1>Namespace for PIDF service capability extension</h1>
<h2>urn:ietf:params:xml:ns:pidf:caps</h2>
<p>See <a href="[[[URL of published RFC]]]">RFCXXXX</a>.</p>
</body>
</html>
END
8. Security Considerations
All security considerations specified in RFC3859 [1] and in RFC3863
[4] apply to this document. Compared to PIDF [4] this presence
document format may reveal additional information about user's
service and device capabilities. Thus, the PUA SHOULD always obtain
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permission from the user when publishing sensitive information using
this extension.
Because presence is very privacy-sensitive information, the transport
protocol for the presence information SHOULD have capabilities to
protect protocol messages from possible threats, such as
eavesdropping, corruption, tamper and replay attacks. If such
security measures are not used, eavesdroppers can learn sensitive
information about the user. It may be possible for a third party to
modify the user's presence information. This can lead to a situation
that users receiving presentity's presence information can take
incorrect actions based on false information. The protocols SHOULD
be able to use security mechanisms which are standardized or being
standardized in IETF. However, it depends on the actual transport
protocols which security mechanisms should be used, and it is beyond
the scope of this memo.
9. Acknowledgments
Authors of this document would like to thank following people for
their contributions and valuable comments: Paul Kyzivat, Jonathan
Rosenberg, Markus Isomaki, Eva Leppanen, Miguel Garcia, Jari
Urpalainen, and Hisham Khartabil.
10. References
10.1. Normative references
[1] Peterson, J., "Common Profile for Presence (CPP)", RFC 3859,
August 2004.
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[3] Day, M., Rosenberg, J., and H. Sugano, "A Model for Presence
and Instant Messaging", RFC 2778, February 2000.
[4] Sugano, H., Fujimoto, S., Klyne, G., Bateman, A., Carr, W., and
J. Peterson, "Presence Information Data Format (PIDF)",
RFC 3863, August 2004.
[5] Schulzrinne, H., Rosenberg, J., and P. Kyzivat, "Indicating
User Agent Capabilities in the Session Initiation Protocol
(SIP)", RFC 3840, August 2004.
[6] Klyne, G., "MIME Content Types in Media Feature Expressions",
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RFC 2913, September 2000.
[7] Hoffman, P., "Registration of Charset and Languages Media
Features Tags", RFC 2987, November 2000.
[8] Moats, R., "A URN namespace for IETF documents", RFC 2648,
Aug. 1999.
[9] Mealling, M., "The IETF XML Registry", RFC 3688, BCP 81,
January 2004.
[10] Rosenberg, J., "A Data Model for Presence", RFC 4479,
July 2006.
[11] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) part one: Format of Internet Message Bodies",
RFC 2045, November 1996.
10.2. Informative references
[12] Peterson, J., "Common Profile for Instant Messaging (CPIM)",
RFC 3860, August 2004.
[13] Handley, M. and V. Jacobson, "SDP: Session Description
Protocol", RFC 2327, April 1998.
[14] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) part two: Media Types", RFC 2046,
November 1996.
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Authors' Addresses
Mikko Lonnfors
Nokia
P.O. Box 321
Helsinki
Finland
Phone: +358 71 8008000
Email: mikko.lonnfors@nokia.com
Krisztian Kiss
Nokia
12278 Scripps Summit Drive
San Diego, CA 92131
USA
Phone: +18583357341
Email: krisztian.kiss@nokia.com
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Intellectual Property Statement
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http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
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this standard. Please address the information to the IETF at
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This document and the information contained herein are provided on an
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except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
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