SIMPLE WG M. Lonnfors
Internet-Draft K. Kiss
Intended status: Standards Track Nokia
Expires: September 19, 2008 March 18, 2008
Session Initiation Protocol (SIP) User Agent Capability Extension to
Presence Information Data Format (PIDF)
draft-ietf-simple-prescaps-ext-09
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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 . . . . . . . . . . . . . . . . . . 8
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 . . . . . . . . . . . . . . . 10
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 . . . . . . . . . . . . . . . . . . . 14
3.3.1. <devcaps> element . . . . . . . . . . . . . . . . . . 14
3.3.2. <mobility> element . . . . . . . . . . . . . . . . . . 14
3.3.3. <description> element . . . . . . . . . . . . . . . . 15
4. Usage guidelines . . . . . . . . . . . . . . . . . . . . . . . 15
4.1. Use of <supported> and <notsupported> elements . . . . . . 16
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. XML schema definitions . . . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26
7.1. URN sub-namespace registration for
'urn:ietf:params:xml:ns:pidf:caps' . . . . . . . . . . . . 26
8. Security Considerations . . . . . . . . . . . . . . . . . . . 27
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.1. Normative references . . . . . . . . . . . . . . . . . . . 27
10.2. Informative references . . . . . . . . . . . . . . . . . . 28
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 28
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Intellectual Property and Copyright Statements . . . . . . . . . . 30
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1. Introduction
Common Profile for Presence (CPP) [RFC3859] and Common Profile for
Instant Messaging (CPIM) [RFC3860] 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) [RFC3863]. 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 [RFC3863].
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]. 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 [RFC3863] 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]. 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.
The User Agent Capabilities extension [RFC3840] defines a set of
extensions which allow user agents 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 PIDF extensions which enable SIP presence
implementations to utilize User Agent Capabilities [RFC3840] within
presence documents.
This extension does not replace media negotiation mechanisms defined
for SIP (e.g. SDP [RFC4566]). 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 [RFC2119].
This memo makes use of the vocabulary defined in [RFC2778], and in
[RFC3863].
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 [RFC3863] 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] can be
provided as a part of presence data. Additionally, this memo
includes the "type" feature tag [RFC2913], "message" media type
feature tag [RFC4569] and the "language" feature tag [RFC4646]
definitions. Bringing these features in the PIDF means mapping them
to an XML formatted structure.
The presence data model [RFC4479] 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] and
extended by [RFC3688].
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 [RFC3863].
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> [RFC3863] 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 can contain any number of optional extension
attributes from other namespaces.
3.2.2. <audio> element
The <audio> element indicates that the service supports audio as a
streaming media type as defined in [RFC3840].
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].
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The <application> element is a boolean type and does not have any
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].
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].
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].
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].
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.
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3.2.8. <message> element
The <message> element indicates that the service supports messaging
as a streaming media type as defined in [RFC4569].
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].
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 [RFC2045]. Only
lower-case letters SHOULD be used.
3.2.10. <automata> element
The <automata> element indicates whether the service represents an
automaton (such as a voicemail server, conference server, or
recording device) or a human as defined in [RFC3840].
The <automata> element is a boolean type and does not have any
attributes. The value 'true' indicates that the service represents
an automaton 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].
The <class> element can contain two elements: <supported> and
<notsupported>. Classes that are supported by the service can be
listed under <supported> element and classes that are not supported
by the service can be 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] as:
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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
value of an extension element. If the appropriate value is not
registered it SHOULD be registered as defined in [RFC3840].
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].
The <duplex> element can contain two elements: <supported> and
<notsupported>. Duplex modes that are supported by the service can
be listed under <supported> element and duplex modes that are not
supported by the service can be 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] 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 registered as defined in [RFC3840].
3.2.13. <description> element
The <description> element provides a textual description of the
service as defined in [RFC3840].
The <description> element is of string type and does not have any
attributes.
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The <description> element SHOULD be labeled with the 'xml:lang'
attribute to indicate its language and script. The specification
allows multiple occurrences of this elements so that the presentity
can convey <description> elements in multiple scripts and languages.
If no 'xml:lang' attribute is provided, the default value is
"i-default" as defined in [RFC2277].
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>
and <notsupported>. Event packages that are supported by the service
can be listed under <supported> element and event packages that are
not supported by the service can be listed under <notsupported>
element.
The <supported> and <notsupported> elements can contain any values
from the IANA SIP event types namespace registry followed by any
number of optional extension elements from other namespaces. As of
today the IANA SIP event types namespace registry includes the
following packages: <conference>, <dialog>, <kpml>, <message-
summary>, <poc-settings>, <presence>, <reg>, <refer>, <Siemens-RTP-
Stats>, <spirits-INDPs>, <spirits-user-prof> and <winfo>.
3.2.15. <priority> element
The <priority> element indicates the call priorities the service is
willing to handle as defined in [RFC3840].
The <priority> element can contain two elements: <supported> and
<notsupported>. Priority values that are supported by the service
can be listed under <supported> element and priority values that are
not supported by the service can be 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.
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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
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].
The <methods> element can contain two elements: <supported> and
<notsupported>. Methods that are supported by the service can be
listed under <supported> element and methods that are not supported
by the service can be 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
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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].
The <extensions> element can contain two elements: <supported> and
<notsupported>. Extensions that are supported by the service can be
listed under <supported> element and extensions that are not
supported by the service can be listed under <notsupported> element.
The <supported> and <notsupported> elements can contain any values
from the IANA SIP parameters registry option tags table followed by
any number of optional extension elements from other namespaces. As
of today the IANA SIP parameters registry includes the following
option tags: <rel100>, <early-session>, <eventlist>, <from-change>,
<gruu>, <histinfo>, <join>, <norefersub>, <path>, <precondition>,
<pref>, <privacy>, <replaces>, <resource-priority>, <sdp-anat>, <sec-
agree>, <tdialog> and <timer>.
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 [RFC3840].
The <schemes> element can contain two elements: <supported> and
<notsupported>. Schemes that are supported by the service can be
listed under <supported> element and schemes that are not supported
by the service can be 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].
The <actor> element can contain two elements: <supported> and
<notsupported>. Actor types that are supported by the service can be
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listed under <supported> element and actor types that are not
supported by the service can be 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] 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).
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 registered as defined in [RFC3840].
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].
The <isfocus> element is of boolean type and does not have any
attributes. The value 'true' indicates that service is a conference
server and the value 'false' indicates that service does not support
conferencing.
3.2.21. <languages> element
The <languages> element indicates the ability to display particular
human languages as defined in [RFC4646].
The <languages> element can contain two elements: <supported> and
<notsupported>. Languages that are supported by the service can be
listed under <supported> element and languages that are not supported
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by the service can be 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
[RFC4646].
3.3. Device capabilities
Elements belonging to device capabilities are used to describe
dynamic characteristics of a device. 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 [RFC4479].
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> and <description> followed by any number of
optional extension elements from other namespaces.
A <devcaps> element can contain any number of optional extension
attributes from other namespaces.
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].
The <mobility> element can contain two elements: <supported> and
<notsupported>. Mobility modes that are supported by the device can
be listed under <supported> element and all mobility modes that are
not supported by the device can be listed under <notsupported>
element.
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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] 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 registered as defined in [RFC3840].
3.3.3. <description> element
The <description> element provides a textual description of the
device as defined in [RFC3840].
The <description> element is of string type and does not have any
attributes.
The <description> element SHOULD be labeled with the 'xml:lang'
attribute to indicate its language and script. The specification
allows multiple occurrences of this elements so that the presentity
can convey <description> elements in multiple scripts and languages.
If no 'xml:lang' attribute is provided, the default value is
"i-default" as defined in RFC 2277[RFC2277].
4. Usage guidelines
The User Agent Capabilities extension [RFC3840] recommends 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). 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. Also combining
presence document from multiple sources may result in lose or
mismatch of information.
It is RECOMMENDED 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
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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. Because of this watchers
should not expect that the presence information represented by this
extension fully represents the actual presentity's device
capabilities or that signaled SIP session would support certain
capabilities. As explained in section Section 1.2 presence of this
extension does not replace the use of SIP signaling.
4.1. Use of <supported> and <notsupported> elements
PUAs should add information under <supported> and <notsupported>
elements only when they believe it may affect the decision making in
the watcher's end, i.e. information should be relevant and valuable
for the watcher. Listing all possible information under <supported>
and <notsupported> is rarely needed.
For example, if the PUA wants to advertise a message service that
supports MESSAGE method it should add it under <supported> in
<methods> element. Even if the service does not support other
methods it is unlikely that listing all the not supported methods
under <notsupported> would provide any value to the watcher.
In case of conflicting information, i.e. same child element appears
under <supported> and <notsupported> elements with same value, the
watcher can safely assume that the listed capability is supported
regardless of the inclusion of the capability under the
<notsupported> element.
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>
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<caps:description xml:lang="en">
Example service
</caps:description>
<caps:description xml:lang="hu">
Pe'lda szolga'ltata's
</caps:description>
<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>
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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"?>
<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"/>
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<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"
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:anyAttribute namespace="##any" processContents="lax"/>
</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:any namespace="##other" processContents="lax"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute namespace="##any" processContents="lax"/>
</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>
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<!-- CONTROL -->
<xs:simpleType name="controltype">
<xs:restriction base="xs:boolean"/>
</xs:simpleType>
<!-- VIDEO -->
<xs:simpleType name="videotype">
<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"/>
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</xs:sequence>
</xs:complexType>
<!-- DUPLEX -->
<xs:complexType name="duplextype">
<xs:sequence>
<xs:element name="supported" type="tns:duplextypes"
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="conference" type="xs:string"
minOccurs="0"/>
<xs:element name="dialog" type="xs:string"
minOccurs="0"/>
<xs:element name="kpml" type="xs:string"
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minOccurs="0"/>
<xs:element name="message-summary" type="xs:string"
minOccurs="0"/>
<xs:element name="poc-settings" type="xs:string"
minOccurs="0"/>
<xs:element name="presence" type="xs:string"
minOccurs="0"/>
<xs:element name="reg" type="xs:string"
minOccurs="0"/>
<xs:element name="refer" 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"/>
<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">
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<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"
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>
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<!-- 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="rel100" type="xs:string" minOccurs="0"/>
<xs:element name="early-session" type="xs:string" minOccurs="0"/>
<xs:element name="eventlist" type="xs:string" minOccurs="0"/>
<xs:element name="from-change" type="xs:string" minOccurs="0"/>
<xs:element name="gruu" type="xs:string" minOccurs="0"/>
<xs:element name="hist-info" type="xs:string" minOccurs="0"/>
<xs:element name="join" type="xs:string" minOccurs="0"/>
<xs:element name="norefersub" 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"/>
<xs:element name="privacy" type="xs:string" minOccurs="0"/>
<xs:element name="replaces" type="xs:string" minOccurs="0"/>
<xs:element name="resource-priority" type="xs:string" minOccurs="0"/>
<xs:element name="sdp-anat" type="xs:string" minOccurs="0"/>
<xs:element name="sec-agree" type="xs:string" minOccurs="0"/>
<xs:element name="tdialog" type="xs:string" minOccurs="0"/>
<xs:element name="timer" 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"/>
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</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>
<!-- 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>
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</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 1
7. IANA Considerations
This memo calls for IANA to register one new XML namespace URNs as
defined in [RFC3688].
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:
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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] and [RFC3863]
apply to this document. Compared to PIDF [RFC3863] this presence
document format may reveal additional information about user's
service and device capabilities. Thus, the PUA SHOULD always obtain
permission from the user when publishing sensitive information using
this extension.
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
[RFC3859] Peterson, J., "Common Profile for Presence (CPP)",
RFC 3859, August 2004.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC3863] Sugano, H., Fujimoto, S., Klyne, G., Bateman, A., Carr,
W., and J. Peterson, "Presence Information Data Format
(PIDF)", RFC 3863, August 2004.
[RFC3840] Schulzrinne, H., Rosenberg, J., and P. Kyzivat,
"Indicating User Agent Capabilities in the Session
Initiation Protocol (SIP)", RFC 3840, August 2004.
[RFC2913] Klyne, G., "MIME Content Types in Media Feature
Expressions", RFC 2913, September 2000.
[RFC4646] Phillips, A. and M. Davis, "Tags for Identifying
Languages", RFC 4646, September 2006.
[RFC3688] Mealling, M., "The IETF XML Registry", RFC 3688, BCP 81,
January 2004.
[RFC4479] Rosenberg, J., "A Data Model for Presence", RFC 4479,
July 2006.
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) part one: Format of Internet Message
Bodies", RFC 2045, November 1996.
[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Languages", RFC 2277, January 1998.
10.2. Informative references
[RFC4569] Camarillo, G., "Internet Assigned Numbers Authority (IANA)
Registration of the Message Media Feature Tag", RFC 4569,
July 2006.
[RFC3860] Peterson, J., "Common Profile for Instant Messaging
(CPIM)", RFC 3860, August 2004.
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
Description Protocol", RFC 4566, July 2006.
[RFC2778] Day, M., Rosenberg, J., and H. Sugano, "A Model for
Presence and Instant Messaging", RFC 2778, February 2000.
[RFC2648] Moats, R., "A URN namespace for IETF documents", RFC 2648,
Aug. 1999.
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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
313 Fairchild Dr
Mountain View, CA 94043
US
Phone: +1 650 391 5969
Email: krisztian.kiss@nokia.com
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Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
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Lonnfors & Kiss Expires September 19, 2008 [Page 30]