SIPPING J. Rosenberg Internet-Draft dynamicsoft Expires: April 25, 2005 H. Schulzrinne Columbia University O. Levin, Ed. Microsoft Corporation October 25, 2004 A Session Initiation Protocol (SIP) Event Package for Conference State draft-ietf-sipping-conference-package-06 Status of this Memo This document is an Internet-Draft and is subject to all provisions of section 3 of RFC 3667. By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 25, 2005. Copyright Notice Copyright (C) The Internet Society (2004). Abstract This document defines a conference event package for the Session Initiation Protocol (SIP) Events framework, along with a data format used in notifications for this package. The conference package Rosenberg, et al. Expires April 25, 2005 [Page 1] Internet-Draft Conference Package October 2004 allows users to subscribe to a conference URI. Notifications are sent about changes in the membership of this conference and optionally about changes in the state of additional conference components. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Conference Event Package . . . . . . . . . . . . . . . . . . . 7 3.1 Event Package Name . . . . . . . . . . . . . . . . . . . . 7 3.2 SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . . 7 3.3 Subscription Duration . . . . . . . . . . . . . . . . . . 7 3.4 NOTIFY Bodies . . . . . . . . . . . . . . . . . . . . . . 8 3.5 Notifier Processing of SUBSCRIBE Requests . . . . . . . . 8 3.6 Notifier Generation of NOTIFY Requests . . . . . . . . . . 8 3.7 Subscriber Processing of NOTIFY Requests . . . . . . . . . 9 3.8 Handling of Forked Requests . . . . . . . . . . . . . . . 9 3.9 Rate of Notifications . . . . . . . . . . . . . . . . . . 9 3.10 State Agents . . . . . . . . . . . . . . . . . . . . . . . 9 4. Conference Data Model . . . . . . . . . . . . . . . . . . . . 11 5. Constructing Coherent State . . . . . . . . . . . . . . . . . 12 6. Conference Data . . . . . . . . . . . . . . . . . . . . . . . 14 6.1 Conference Information . . . . . . . . . . . . . . . . . . 14 6.1.1 Conference Type . . . . . . . . . . . . . . . . . . . 14 6.1.1.1 conference-description of conference-description-type . . . . . . . . . . . 14 6.1.1.2 host-info of host-type . . . . . . . . . . . . . . 14 6.1.1.3 conference-state of conference-state-type . . . . 15 6.1.1.4 user of user-type . . . . . . . . . . . . . . . . 15 6.1.1.5 sidebars-by-ref of uris-type . . . . . . . . . . . 15 6.1.1.6 sidebar-by-val of conference-type . . . . . . . . 15 6.1.2 Conference Description Type . . . . . . . . . . . . . 15 6.1.2.1 display-text of string type . . . . . . . . . . . 15 6.1.2.2 subject of string type . . . . . . . . . . . . . . 15 6.1.2.3 free-text of string type . . . . . . . . . . . . . 15 6.1.2.4 keywords of keywords-type . . . . . . . . . . . . 16 6.1.2.5 web-page of anyURI type . . . . . . . . . . . . . 16 6.1.2.6 conf-uris of uris-type . . . . . . . . . . . . . . 16 6.1.2.7 service-uris of uris-type . . . . . . . . . . . . 16 6.1.2.8 maximum-user-count of user-count-type . . . . . . 16 6.1.2.9 available-media of conference-medias-type . . . . 16 6.1.3 Host Type . . . . . . . . . . . . . . . . . . . . . . 16 6.1.3.1 display-text of string type . . . . . . . . . . . 16 6.1.3.2 web-page of anyURI type . . . . . . . . . . . . . 17 6.1.3.3 uris of uris-type . . . . . . . . . . . . . . . . 17 6.1.4 Conference State Type . . . . . . . . . . . . . . . . 17 6.1.4.1 user-count of user-count-type . . . . . . . . . . 17 Rosenberg, et al. Expires April 25, 2005 [Page 2] Internet-Draft Conference Package October 2004 6.1.4.2 security-level of security-level-type . . . . . . 17 6.1.4.3 active of Boolean type . . . . . . . . . . . . . . 17 6.1.4.4 locked of Boolean type . . . . . . . . . . . . . . 17 6.1.4.5 recording of uris-type . . . . . . . . . . . . . . 17 6.1.4.6 active-media of conference-medias-type . . . . . . 18 6.1.5 User Type . . . . . . . . . . . . . . . . . . . . . . 18 6.1.5.1 display-text of string type . . . . . . . . . . . 18 6.1.5.2 associated-aors of anyURI type . . . . . . . . . . 18 6.1.5.3 roles of user-roles-type . . . . . . . . . . . . . 18 6.1.5.4 language of language type . . . . . . . . . . . . 19 6.1.5.5 cascaded-focus of anyURI type . . . . . . . . . . 19 6.1.5.6 endpoint of endpoint-type . . . . . . . . . . . . 19 6.1.6 Endpoint Type . . . . . . . . . . . . . . . . . . . . 19 6.1.6.1 display-text of string type . . . . . . . . . . . 20 6.1.6.2 referred of execution-type . . . . . . . . . . . . 20 6.1.6.3 state of endpoint-state-type . . . . . . . . . . . 20 6.1.6.4 joining-method of joining-type . . . . . . . . . . 21 6.1.6.5 joining-info of execution-type . . . . . . . . . . 21 6.1.6.6 disconnection-method of disconnection-type . . . . 22 6.1.6.7 disconnection-info of disconnection-type . . . . . 22 6.1.6.8 whispering-to of uris-type . . . . . . . . . . . . 22 6.1.6.9 media of media-type . . . . . . . . . . . . . . . 22 6.1.7 Media Type . . . . . . . . . . . . . . . . . . . . . . 23 6.1.7.1 display-text of string type . . . . . . . . . . . 23 6.1.7.2 proto of string type . . . . . . . . . . . . . . . 23 6.1.7.3 ssrc of string type . . . . . . . . . . . . . . . 23 6.1.7.4 label of string type . . . . . . . . . . . . . . . 24 6.1.7.5 state of media-state-type . . . . . . . . . . . . 24 6.1.7.6 snd-status of media-state-type . . . . . . . . . . 24 6.1.7.7 rcv-status state of media-state-type . . . . . . . 24 6.1.7.8 call of call-type . . . . . . . . . . . . . . . . 24 7. Schema . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 8.1 Basic Example . . . . . . . . . . . . . . . . . . . . . . 33 8.2 Rich Example . . . . . . . . . . . . . . . . . . . . . . . 35 9. Security Considerations . . . . . . . . . . . . . . . . . . . 40 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 41 10.1 conference Event Package Registration . . . . . . . . . . 41 10.2 application/conference-info+xml MIME Registration . . . . 41 10.3 URN Sub-Namespace Registration for urn:ietf:params:xml:ns:conference-info . . . . . . . . . . 41 10.4 XML Schema Registration . . . . . . . . . . . . . . . . . 42 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 43 12. Changes History . . . . . . . . . . . . . . . . . . . . . . 44 12.1 Changes since -05 . . . . . . . . . . . . . . . . . . . . 44 12.2 Changes since -04 . . . . . . . . . . . . . . . . . . . . 44 12.3 Changes since -03 . . . . . . . . . . . . . . . . . . . . 44 12.4 Changes since -02 . . . . . . . . . . . . . . . . . . . . 44 Rosenberg, et al. Expires April 25, 2005 [Page 3] Internet-Draft Conference Package October 2004 12.5 Changes since -01 . . . . . . . . . . . . . . . . . . . . 45 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 46 13.1 Normative References . . . . . . . . . . . . . . . . . . . . 46 13.2 Informative References . . . . . . . . . . . . . . . . . . . 46 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 47 Intellectual Property and Copyright Statements . . . . . . . . 49 Rosenberg, et al. Expires April 25, 2005 [Page 4] Internet-Draft Conference Package October 2004 1. Introduction The Session Initiation Protocol (SIP) [6] Events framework Events Framework [7] defines general mechanisms for subscribing to, and receiving notifications of, events within SIP networks. It introduces the notion of a package, which is a specific "instantiation" of the events framework for a well-defined set of events. Here, we define an event package for SIP conferences. This package provides the conference notification service as outlined in the SIP conferencing framework [15]. As described there, subscriptions to a conference URI are routed to the focus that is handling the conference. It acts as the notifier, and provides clients with updates on conference state. The information provided by this package is comprised of conference identifier(s), conference participants (optionally with their statuses and media description), conference sidebars, conference service URIs, etc. Rosenberg, et al. Expires April 25, 2005 [Page 5] Internet-Draft Conference Package October 2004 2. Terminology In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in RFC 2119 [2] and indicate requirement levels for compliant implementations. Rosenberg, et al. Expires April 25, 2005 [Page 6] Internet-Draft Conference Package October 2004 3. Conference Event Package The conference event package allows a user to subscribe to a conference. In SIP, conferences are represented by URIs. These URIs route to a SIP user agent, called a focus, that is responsible for ensuring that all users in the conference can communicate with each other, as described in Conferencing Framework [15]. The focus has sufficient information about the state of the conference to inform subscribers about it. It is possible a participant in the conference may in fact be another focus. In order to provide a more complete participant list, the focus MAY subscribe to the conference package of the other focus to discover the participant list in the cascaded conference. This information can then be included in notifications by using of the "cascaded-focus" element as specified by this package. This section provides the details for defining a SIP Events package, as specified by RFC 3265 [7]. 3.1 Event Package Name The name of this event package is "conference". This package name is carried in the Event and Allow-Events header, as defined in RFC 3265 [7]. 3.2 SUBSCRIBE Bodies A SUBSCRIBE for a conference package MAY contain a body. This body defines a filter to apply to the subscription. Filter documents are not specified in this document, and at the time of writing, are expected to be the subject of future standardization activity. A SUBSCRIBE for a conference package MAY be sent without a body. This implies the default subscription filtering policy. The default policy is: o Notifications are generated every time there is any change in the state of the conference. o Notifications do not normally contain full state; rather, they only indicate the state that has changed. The exception is a NOTIFY sent in response to a SUBSCRIBE. These NOTIFYs contain the full state of the information requested by the subscriber. 3.3 Subscription Duration The default expiration time for a subscription to a conference is one hour. Once the conference ends, all subscriptions to that particular conference are terminated, with a reason of "noresource" RFC 3265 Rosenberg, et al. Expires April 25, 2005 [Page 7] Internet-Draft Conference Package October 2004 [7]. 3.4 NOTIFY Bodies As described in RFC 3265 [7], the NOTIFY message will contain bodies that describe the state of the subscribed resource. This body is in a format listed in the Accept header field of the SUBSCRIBE, or a package-specific default if the Accept header field was omitted from the SUBSCRIBE. In this event package, the body of the notification contains a conference information document. This document describes the state of a conference. All subscribers and notifiers MUST support the "application/conference-info+xml" data format described in Section 6. The subscribe request MAY contain an Accept header field. If no such header field is present, it has a default value of "application/conference-info+xml". If the header field is present, it MUST include "application/conference-info+xml", and MAY include any other types. Of course, the notifications generated by the server MUST be in one of the formats specified in the Accept header field in the SUBSCRIBE request. 3.5 Notifier Processing of SUBSCRIBE Requests The conference information contains very sensitive information. Therefore, all subscriptions SHOULD be authenticated and then authorized before approval. Authorization policy is at the discretion of the administrator, as always. However, a few recommendations can be made. It is RECOMMENDED that all users in the conference be allowed to subscribe to the conference. 3.6 Notifier Generation of NOTIFY Requests Notifications MUST be generated for the conference state when a new participant joins (i.e. gets "connected" to) or a participant leaves (i.e. gets "disconnected" from) the conference. Subject to a local focus policy, additional changes in participants' status, changes in their media types, and other optional information MAY be reported by the focus. Changes in sidebar rosters SHOULD be reported by the focus to their participants and MAY be reported to others, subject to local policy. Rosenberg, et al. Expires April 25, 2005 [Page 8] Internet-Draft Conference Package October 2004 Changes in conference identifiers and service URIs SHOULD be reported by the focus to the Conference package subscribers. Changes in other conference state information MAY be reported by the focus to the Conference package subscribers. 3.7 Subscriber Processing of NOTIFY Requests The SIP Events framework expects packages to specify how a subscriber processes NOTIFY requests in any package specific ways, and in particular, how it uses the NOTIFY requests to construct a coherent view of the state of the subscribed resource. Typically, the NOTIFY for the conference package will only contain information about those users whose state in the conference has changed. To construct a coherent view of the total state of all users, a subscriber to the conference package will need to combine NOTIFYs received over time. Notifications within this package can convey partial information; that is, they can indicate information about a subset of the state associated with the subscription. This means that an explicit algorithm needs to be defined in order to construct coherent and consistent state. The details of this mechanism are specific to the particular document type. See Section 5 for information on constructing coherent information from an application/conference-info+xml document. 3.8 Handling of Forked Requests By their nature, the conferences supported by this package are centralized. Therefore, SUBSCRIBE requests for a conference should not generally fork. Users of this package MUST NOT install more than a single subscription as a result of a single SUBSCRIBE request. 3.9 Rate of Notifications For reasons of congestion control, it is important that the rate of notifications not become excessive. As a result, it is RECOMMENDED that the server not generate notifications for a single subscriber at a rate faster than once every 5 seconds. 3.10 State Agents Conference state is ideally maintained in the element in which the conference resides. Therefore, the elements that maintain the conference are the ones best suited to handle subscriptions to it. Therefore, the usage of state agents is NOT RECOMMENDED for this Rosenberg, et al. Expires April 25, 2005 [Page 9] Internet-Draft Conference Package October 2004 package. Rosenberg, et al. Expires April 25, 2005 [Page 10] Internet-Draft Conference Package October 2004 4. Conference Data Model Conference information is an XML document that MUST be well-formed and SHOULD be valid. Dialog information documents MUST be based on XML 1.0 and MUST be encoded using UTF-8. This specification makes use of XML namespaces for identifying dialog information documents and document fragments. The namespace URI for elements defined by this specification is a URN [3], using the namespace identifier 'ietf' defined by [4] and extended by [1]. This URN is: The conference information is described by a hierarchal XML structure with the root element "conference-info". The root element is the only element in the schema that carries meaningful version number for all the elements in the document. The whole conference information is associated with this version number. All sub-elements in the "conference-info" hierarchal XML structure can be classified in two groups: those that carry relatively small amount of data and those that can potentially carry a lot of data. During partial notifications, the light elements are updated as atomic pieces of data. On the other hand, elements that can carry a substantial amount of data have the general "state" attribute attached to them. That is in order to support partial notifications for their content. A "state" attribute of a child element in the document MUST adhere to its parent "state". It means that if the parent's "state" is "full", the state of its children MUST be "full". If the parent's "state" is "partial", the state of its children MAY be either "partial", "full", or "deleted". For elements with the optional "state" attribute, if the attribute is omitted from the notification for the element, it means that the reported element's state is "full". All sub-elements, with possible multiple appearances under a common parent, have keys defined to them in order to uniquely identify each element among others of the same type in the partial notification event. Rosenberg, et al. Expires April 25, 2005 [Page 11] Internet-Draft Conference Package October 2004 5. Constructing Coherent State A Conference package subscriber MUST initialize the "version" attribute from the "conference-info" element with the value in the first document received. The conference package subscriber locally maintains a local element for each element in the schema and a table for each element with key(s) in the schema and indexed by these key(s). Each time a new NOTIFY is received, the value of the local version number and the "version" attribute in the new received document are compared. If the value in the new document is one higher than the local version number, the local version number is increased by one, and the document is processed. If the value in the document is more than one higher than the local version number, the local version number is set to the value in the new document, the document is processed, and the subscriber SHOULD generate a refresh request to trigger a full state notification. If the value in the document is less than the local version, the document is discarded without processing. Further processing of the conference information document depends on whether it contains full or partial state. If it contains full state, indicated by the value of the "state" attribute in the "conference-info" element, the whole local content is flushed and repopulated from the document. If it contains "deleted" state, indicated by the value of the "state" attribute in the "conference-info" element, it means that the conference ceased to exist and the subscriber SHOULD terminate the SUBSCRIBE dialog. If the document contains partial state, as indicated by the value of the "state" attribute in the "conference-info" element, the document is used to update the local content as described below. Starting from outer elements in the received document, 1. If the parent element contains "full" state, the whole local element content is flushed and repopulated from the document. 2. Otherwise, if the parent element contains "deleted" state, the whole element MUST be removed from the local content. 3. Otherwise, if the parent element contains "partial" state: 3.1 For elements with keys, the subscriber compares the keys received in the update with the keys in the local tables. Rosenberg, et al. Expires April 25, 2005 [Page 12] Internet-Draft Conference Package October 2004 3.1.1 If a key does not exist in the local table, a row is added, and its content is set to the element information from the update. 3.1.2 Otherwise, if a key of the same value does exist, for each sub-element in the row the algorithm is applied from step 2.2. 3.2 For each atomic element received in the schema, the element is replaced with the new information as a whole. Also, for each non-atomic element received in the schema with either no "state" attribute included or the state attribute is set to "full", the element is replaced with the new information as a whole. 3.2.1 If an element, which doesnĘt have key(s), is updated or created such that its content is empty, that element MAY be removed from the local content at any time. 3.3 For each non-atomic element with the state attribute set to "partial", the algorithm is applied recursively starting from step 3. Rosenberg, et al. Expires April 25, 2005 [Page 13] Internet-Draft Conference Package October 2004 6. Conference Data urn:ietf:params:xml:ns:conference-info A conference information document begins with the root element tag "conference-info". 6.1 Conference Information A conference instance is defined as a top level element "conference-info" of a type "conference-type". Sections below describe the complex types composing the hierarchal "conference-type". The full XML schema is defined in Section 7. 6.1.1 Conference Type This type has the following attributes: version: This mandatory attribute allows the recipient of conference information documents to properly order them. Versions start at 0 and increment by one for each new document sent to a subscriber. Versions are scoped within a subscription. Versions MUST be represented using a 32 bit integer. entity: This mandatory attribute contains the conference URI that identifies the conference being described in the document. state: This mandatory attribute indicates whether the document contains the whole conference information ("full"), only the information that has changed since the previous document ("partial"), or the conference ceased to exist ("deleted"). For more details see Section 5. This type defines an extendable sequence of the following optional child elements: 6.1.1.1 conference-description of conference-description-type This element contains conference information that is derived from system conference policies, is set before the conference activation, and is rarely changed during the conference lifetime. 6.1.1.2 host-info of host-type This element contains information about the entity that hosts the conference. This information is set before the conference activation, and is rarely changed during the conference lifetime, Rosenberg, et al. Expires April 25, 2005 [Page 14] Internet-Draft Conference Package October 2004 unless the whole conference is moved to be hosted by another entity. 6.1.1.3 conference-state of conference-state-type This element contains the dynamic information about the current state of the focus. 6.1.1.4 user of user-type This element contains the information about a participant in the conference. The element of the user-type can have unbounded number of appearance in the conference-type for each participant in the conference. 6.1.1.5 sidebars-by-ref of uris-type This element provides a pointer to sidebar information through sidebar URIs. The recipient of the information can then subscribe to sidebar information independently from the main Conference package subscription. 6.1.1.6 sidebar-by-val of conference-type This element provides sidebar information as a part of the main Conference package information. 6.1.2 Conference Description Type This element contains the "state" attribute which can contain the values "full", "partial", or deleted". This type defines an extendable sequence of the following optional child elements: 6.1.2.1 display-text of string type This element contains text information about the conference. 6.1.2.2 subject of string type This element contains information about the subject of a conference. 6.1.2.3 free-text of string type This element contains free form text about the conference. Rosenberg, et al. Expires April 25, 2005 [Page 15] Internet-Draft Conference Package October 2004 6.1.2.4 keywords of keywords-type This element contains a list of keywords which describe the conference topic. 6.1.2.5 web-page of anyURI type This element contains a URI of a web page that contains information related to the conference. 6.1.2.6 conf-uris of uris-type This element contains information about additional conference URIs that this conference can be accessed by. Examples of such URIs include h323: [14] and tel: [13] URIs. 6.1.2.7 service-uris of uris-type This element contains the service-related URIs. These URIs can be used to manipulate the conference policies or state, for example. 6.1.2.8 maximum-user-count of user-count-type This element contains a count of the maximum number of users permitted in the conference. The count can be specified for all participants in total (using the sub-element with value "any") or count the users by their roles in the conference. 6.1.2.9 available-media of conference-medias-type This element contains information about the media types available in a conference. The "entry" sub-element MUST be a value registered for "proto" of SDP [12]. 6.1.3 Host Type This element contains the "state" attribute which can contain the values "full", "partial", or deleted". This type defines an extendable sequence of the following optional child elements: 6.1.3.1 display-text of string type This element contains display text information about the user hosting the conference. Rosenberg, et al. Expires April 25, 2005 [Page 16] Internet-Draft Conference Package October 2004 6.1.3.2 web-page of anyURI type This element contains a web page URI about the user hosting the conference. 6.1.3.3 uris of uris-type The "entity" sub-element contains additional URIs relating to the user hosting the conference. 6.1.4 Conference State Type This element contains the "state" attribute which can contain the values "full", "partial", or deleted". This type defines an extendable sequence of the following optional child elements. 6.1.4.1 user-count of user-count-type This element contains a count of the current number of users in the conference. The count can be specified for all participants in total (using the sub-element with value "any") or count the users by their roles in the conference. 6.1.4.2 security-level of security-level-type This element contains information about the conference security level. The values can be "none", "low", "medium", or "high". 6.1.4.3 active of Boolean type This element contains information about whether the conference is currently active or not. 6.1.4.4 locked of Boolean type This element contains information about whether the conference is currently locked. In this context, locked means that the conference roster can not be added to (although participants may leave or be removed from the conference). 6.1.4.5 recording of uris-type The "entry" sub-element contains URIs related to the recording of the conference. Rosenberg, et al. Expires April 25, 2005 [Page 17] Internet-Draft Conference Package October 2004 6.1.4.6 active-media of conference-medias-type This element contains information about the media types currently active in the conference which is a subset of those listed in the "available-media" element. 6.1.5 User Type This type has the following attributes: entity: The mandatory attribute contains the URI for the user in the conference. This is a logical identifier, which corresponds to the authenticated identity of the participant. The "entity" attribute MUST be unique in the user element list because it is used as the key in partial notifications about users' state. An anonymous participant in a conference SHOULD be represented by an anonymous URI generated by the focus. For multiple anonymous participants, the focus must ensure that each anonymous URI is unique. The guidelines for generating anonymous URIs in RFC 3323 [8] should be followed. For example, "Anonymous1" could be used for a participant requesting privacy. state: This mandatory attribute indicates whether the document contains the whole conference information ("full"), only the information that has changed since the previous document ("partial"), or the conference ceased to exist ("deleted"). This type defines an extendable sequence of the following optional child elements. 6.1.5.1 display-text of string type This element contains the display text for the user. 6.1.5.2 associated-aors of anyURI type This element contains associated URIs of the user. Usually this information will be manually provided by a system administrator showing the logical association between signaling entities otherwise independent. 6.1.5.3 roles of user-roles-type This element contains the roles of the user. Rosenberg, et al. Expires April 25, 2005 [Page 18] Internet-Draft Conference Package October 2004 6.1.5.4 language of language type This element contains the language used by the user. 6.1.5.5 cascaded-focus of anyURI type This element contains a conference URI (different from the main conference URI) for users that are connected to the main conference as a result of focus cascading. In accordance with the SIP conferencing framework [15], this package allows for representation of peer-to-peer (i.e. "flat") focus cascading only. The actual cascading graph can not be deduced from the information provided in the package alone. Advanced applications can construct the graph by subscribing to both this package and the Dialog Package [16] of the cascaded foci and correlating the relevant information. 6.1.5.6 endpoint of endpoint-type This element contains information about an endpoint of the user. The element of the endpoint-type can have unbounded number of appearance in the user-type for each endpoint of the user participating in the conference. In a case when authentication is performed per endpoint (rather than per user) in a system, a focus can be not aware of the logical association among endpoints being used by the same user. In this case the focus MAY present the endpoints as belonging to separate users in the conference schema. In a different case, due to privacy concerns for a user the focus may want to shield the information about multiple endpoints from the recipients of the Conference document. To do so the focus MAY aggregate the multiple endpoint information into a single endpoint element under this user. 6.1.6 Endpoint Type This type has the following attributes: entity: The mandatory attribute contains the endpoint URI for the user in the conference. In SIP terms, this is the Contact URI or GRUU. The "entity" attribute MUST be unique in the endpoint element list because it is used as the key in partial notifications about users' endpoints. An anonymous participant in a conference SHOULD be represented by an anonymous URI generated by the focus. For multiple anonymous participants, the focus must ensure that each anonymous URI is unique. The guidelines for generating anonymous URIs in RFC 3323 [8] should be followed. Rosenberg, et al. Expires April 25, 2005 [Page 19] Internet-Draft Conference Package October 2004 state: This mandatory attribute indicates whether the element contains the whole endpoint information ("full"), only the information that has changed since the previous document ("partial"), or the endpoint has been deleted from the conference ("deleted"). This type defines an extendable sequence of the following optional child elements. 6.1.6.1 display-text of string type This element contains the display text for the endpoint. 6.1.6.2 referred of execution-type This element contains the URI of the user who's action resulted in this endpoint being brought into the conference (e.g. the user identified by this URI sent a REFER to the focus). 6.1.6.3 state of endpoint-state-type This element contains the state of the endpoint, and can assume the following values: connected: The endpoint is a participant in the conference. Depending on the media policies, he/she can send and receive media to and from other participants. disconnected: The endpoint is not a participant in the conference and no active dialog exists between the endpoint and the focus. on-hold: Active SIP dialog exists between an endpoint and a focus, but endpoint is "on-hold" for this conference, i.e. neither he/she is "hearing" the conference mix, nor is his/her media being mixed in the conference. As an example, the endpoint has asked to join the conference using SIP, but his/her participation is pending based on moderator approval. In the meantime he/she is hearing music-on-hold or some other kind of related content. muted-via-focus: Active SIP dialog exists between an endpoint and a focus and the endpoint can "listen" to the conference, but endpoint's media is not being mixed into the conference. Note that sometimes a subset of endpoint media streams can be muted by focus (such as poor quality video) while others (such as voice or IM) can still be active. In this case, it is RECOMMENDED that the "aggregated" endpoint connectivity "status" reflects the status of the mostly active media. Rosenberg, et al. Expires April 25, 2005 [Page 20] Internet-Draft Conference Package October 2004 pending: Endpoint is not yet in the session, but it is anticipated that he/she will join in the near future. alerting: A PSTN ALERTING or SIP 180 Ringing was returned for the outbound call, endpoint is being alerted. dialing-in: Endpoint is dialing into the conference, not yet in the roster (probably being authenticated). dialing-out: Focus has dialed out to connect the endpoint to the conference, but the endpoint is not yet in the roster (probably being authenticated). disconnecting: Focus is in the process of disconnecting endpoint (either DISCONNECT or BYE was sent to the endpoint's device). Note that the defined transient states (e.g., disconnecting, alerting, etc.) could generate a lot of notifications. Implementations MAY choose not to generate notifications on these to all participants if it will generate too much traffic. 6.1.6.4 joining-method of joining-type This element contains method by which the endpoint joined the conference, and can assume the following values: dialed-in: The endpoint dialed into the conference, i.e. sent INVITE to the focus, which resulted in successful dialog establishment. dialed-out: The focus has brought the endpoint into the conference by sending a successful INVITE to the endpoint. focus-owner: The endpoint is the focus for this conference. This status is used only when a participant UA acts as a conference focus. 6.1.6.5 joining-info of execution-type This element contains information about how the endpoint joined and can contain the following sub-elements: when: This element contains the date and time that the endpoint joined the conference. Rosenberg, et al. Expires April 25, 2005 [Page 21] Internet-Draft Conference Package October 2004 reason: This element contains the reason the endpoint joined the conference. by: This element contains the URI of the entity who caused the endpoint to join the conference. 6.1.6.6 disconnection-method of disconnection-type This element contains method by which the endpoint departed the conference, and can assume the following values: departed: The endpoint sent a BYE, thus leaving the conference. booted: The endpoint was sent a BYE by the focus, booting him/her out of the conference. Alternatively, the endpoint tried to dial into to conference without success because was rejected by the focus according to local policy decisions. failed: The server tried to bring the endpoint into the conference, but its attempt to contact the specific endpoint resulted in a non-200 class final response. Alternatively, the endpoint tried to dial into the conference without success due to technical reasons. 6.1.6.7 disconnection-info of disconnection-type This element contains information about the endpoint's departure from the conference and can contain the following sub-elements: when: This element contains the date and time that the endpoint departed the conference. reason: This element contains the reason the endpoint departed the conference. by: This element contains the URI of the entity who caused the endpoint to depart the conference. 6.1.6.8 whispering-to of uris-type If an endpoint is participating in a whisper session with other entities, the URIs of these other entities MAY be contained in this element. 6.1.6.9 media of media-type This element contains information about a media stream of this endpoint. The element of the media-type can have unbounded number of Rosenberg, et al. Expires April 25, 2005 [Page 22] Internet-Draft Conference Package October 2004 appearance in the endpoint-type for each media stream of the endpoint. Note that it is possible that media streams listed under a common endpoint MAY be established by separate signaling means and consequently belong to different signaling "calls". 6.1.7 Media Type This type has the following attributes: entity: The mandatory attribute is a unique identifier of a media stream on a per endpoint basis. This attribute is used as a key to identify media streams which may be added and deleted on a dynamic basis during the conference. The value of this element SHOULD correspond to the "mid" value in the SDP document as defined in Grouping of Media Lines in the SDP [9]. state: This mandatory attribute indicates whether the element contains the whole media information ("full"), only the information that has changed since the previous document ("partial"), or the media element has been deleted from the conference document ("deleted"). This type defines an extendable sequence of the following optional child elements. 6.1.7.1 display-text of string type This element contains the display text for the media stream. 6.1.7.2 proto of string type This element contains the media type for the media stream. The value of this element MUST be a value registered for "proto" of SDP [12]. 6.1.7.3 ssrc of string type The "ssrc" element carries the value of SSRC (defined in RTP/RTCP [10]) as generated by the endpoint for the stream it sends. When an RTP mixer generates a CSRC list according to RTP/RTCP [10], it inserts a list of the SSRC identifiers of the sources that contributed to the generation of a particular packet into the RTP header of that packet. "An example application is audio conferencing where a mixer indicates all the talkers whose speech was combined to produce the outgoing packet, allowing the receiver to indicate the current talker, even though all the audio packets contain the same SSRC identifier (that of the mixer)." Rosenberg, et al. Expires April 25, 2005 [Page 23] Internet-Draft Conference Package October 2004 6.1.7.4 label of string type The element "label" carries a unique identifier for this stream among all streams in the conference and is assigned by the focus. The value of this element corresponds to the "label" media attribute in SDP [12] and defined in [19]. 6.1.7.5 state of media-state-type The element "state" contains the state of the media stream and can have the values "active", "inactive", or "muted". 6.1.7.6 snd-status of media-state-type The element "state" contains the state of the sending media stream (from the perspective of the endpoint) and can have the values "active", "inactive", or "muted". 6.1.7.7 rcv-status state of media-state-type The element "state" contains the state of the receiving media stream (from the perspective of the endpoint) and can have the values "active", "inactive", or "muted". 6.1.7.8 call of call-type The "call" element contains the "sip" sub-element which contains the SIP dialog identifier of the endpoint's dialog with the focus. The "sip" element includes sub-elements "display-text", "call-id", "to-tag", "from-tag" Rosenberg, et al. Expires April 25, 2005 [Page 24] Internet-Draft Conference Package October 2004 7. Schema Rosenberg, et al. Expires April 25, 2005 [Page 25] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 26] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 28] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 29] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 30] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 31] Internet-Draft Conference Package October 2004 Rosenberg, et al. Expires April 25, 2005 [Page 32] Internet-Draft Conference Package October 2004 8. Examples 8.1 Basic Example The following is an example conference information document: Agenda: This month's target http://salesgroup.example.com/conference-policies/sales-weekly-meeting.xml 33 audio Bob Hoskins Rosenberg, et al. Expires April 25, 2005 [Page 33] Internet-Draft Conference Package October 2004 Bob's Laptop disconnected departed 2005-03-04T20:00:00Z bad voice quality sip:mike@example.com main audio audio 432424 active Alice connected dialed-out 2005-03-04T20:00:00Z sip:mike@example.com main audio audio 534232 active Rosenberg, et al. Expires April 25, 2005 [Page 34] Internet-Draft Conference Package October 2004 8.2 Rich Example The following is an example conference information document. In this example of a partial state notification, there are 32 participants in a voice conference. The user Bob has been booted from the conference by Mike due to bad voice quality. Note that there are three sidebars in the conference, two are referenced just by their sidebar URI and information about the third sidebar is included in this notification. Also note that while this conference offers both audio and video capabilities, only audio is currently in use. Weekly Sales Meeting Agenda: This month's target xyz sales, meeting, weekly http://sharepoint/salesgroup/ tel:+18005671234 h323:conf545@h323.example.com http://salesgroup.example.com/conference-policies/sales-weekly-meeting.xml 52 Rosenberg, et al. Expires April 25, 2005 [Page 35] Internet-Draft Conference Package October 2004 50 audio video Sales Host http://sharepoint/salesgroup/hosts/ sip:sales@example.com 33 32 medium Rosenberg, et al. Expires April 25, 2005 [Page 36] Internet-Draft Conference Package October 2004 true false http://quicktime.streaming.com/54634/recording.mov http://real.streaming.com/54634/recording.ram audio Bob Hoskins mailto:bob@example.com en Bob's Laptop 2005-03-04T20:00:00Z sip:mike@example.com disconnecting sip:rob@example.com Rosenberg, et al. Expires April 25, 2005 [Page 37] Internet-Draft Conference Package October 2004 sip:helen@example.com dialed-out 2005-03-04T20:00:00Z invitation sip:mike@example.com booted 2005-03-04T20:00:00Z bad voice quality sip:mike@example.com main audio audio 432424 active full info hsjh8980vhsb78 vav738dvbs 8954jgjg8432 sips:conf233@example.com; grid=45 Rosenberg, et al. Expires April 25, 2005 [Page 38] Internet-Draft Conference Package October 2004 sips:conf233@example.com; grid=21 Rosenberg, et al. Expires April 25, 2005 [Page 39] Internet-Draft Conference Package October 2004 9. Security Considerations Subscriptions to conference state can reveal very sensitive information. For this reason, the document recommends authentication and authorization, and provides guidelines on sensible authorization policies. Since the data in notifications is sensitive as well, end-to-end SIP encryption mechanisms using S/MIME SHOULD be used to protect it. Since a focus provides participants identity information using this event package, participant privacy needs to be taken into account. A focus MUST support requests by participants for privacy. Privacy can be indicated by the conference policy - for every participant or select participants. It can also be indicated in the session signaling. In SIP this can be done using the Privacy header field described in RFC 3323 [8]. For a participant requesting privacy, no identity information SHOULD be revealed by the focus such as a URI (e.g. the Address of Record, Contact, or GRUU). For these cases, the anonymous URI generation method outlined in section "User Element" of this document MUST be followed. Rosenberg, et al. Expires April 25, 2005 [Page 40] Internet-Draft Conference Package October 2004 10. IANA Considerations This document registers a SIP event package, a new MIME type, application/conference-info+xml, a new XML namespace, and a new XML schema. 10.1 conference Event Package Registration This specification registers an event package, based on the registration procedures defined in RFC 3265 [7]. The following is the information required for such a registration: Package Name: conference Package or Template-Package: This is a package. Published Document: RFC XXXX (Note to RFC Editor: Please fill in XXXX with the RFC number of this specification). Person to Contact: Jonathan Rosenberg, jdrosen@jdrosen.net. 10.2 application/conference-info+xml MIME Registration MIME media type name: application MIME subtype name: conference-info+xml Mandatory parameters: none Optional parameters: Same as charset parameter application/xml as specified in RFC 3023 [5]. Encoding considerations: Same as encoding considerations of application/xml as specified in RFC 3023 [5]. Security considerations: See Section 10 of RFC 3023 [5] and Section 9 of this specification. Interoperability considerations: none. Published specification: This document. Applications which use this media type: This document type has been used to support SIP conferencing applications. Additional Information: Magic Number: None File Extension: .cif or .xml Macintosh file type code: "TEXT" Personal and email address for further information: Jonathan Rosenberg, Intended usage: COMMON Author/Change controller: The IETF. 10.3 URN Sub-Namespace Registration for urn:ietf:params:xml:ns:conference-info This section registers a new XML namespace, as per the guidelines in [1]. Rosenberg, et al. Expires April 25, 2005 [Page 41] Internet-Draft Conference Package October 2004 URI: The URI for this namespace is urn:ietf:params:xml:ns:conference-info. Registrant Contact: IETF, SIPPING working group, , Jonathan Rosenberg . XML: BEGIN Conference Information Namespace

Namespace for Conference Information

urn:ietf:params:xml:ns:conference-info

See RFCXXXX.

END 10.4 XML Schema Registration This specification registers a schema, as per the guidelines in in [1]. URI: please assign. Registrant Contact: IETF, SIPPING Working Group (sipping@ietf.org), Jonathan Rosenberg (jdrosen@jdrosen.net). XML: The XML can be found as the sole content of Section 7. Rosenberg, et al. Expires April 25, 2005 [Page 42] Internet-Draft Conference Package October 2004 11. Acknowledgements The authors would like to thank Dan Petrie, Sean Olson, Alan Johnston, and Rohan Mahy for their comments and inputs. Rosenberg, et al. Expires April 25, 2005 [Page 43] Internet-Draft Conference Package October 2004 12. Changes History 12.1 Changes since -05 o General schema clean-up. o Definition of common types being used by multiple elements. o Introduction of an "endpoint" element as a part of hierarchy: user/endpoint/media. 12.2 Changes since -04 o o "Sidebar-type" has been removed. "Sidebar" conference element is defined using the general "conference-type". o "Recording" conference attribute has been replaced with "recording" and "streaming" elements within "conference-type". New "recording-type" and "streaming-type" have been introduced. o Attribute "state" has been added to "user-type". o Element "media-stream" within "user-type" has been renamed to "media". o Element "role" within "user-type" has been introduced. o The following statuses have been added to "user-status-type": blocked, pending, calling, ringing, dialing-in, disconnecting, removed. o User status "muted-by-focus" has been renamed to "muted-via-focus". o Attributes "id" and "state" have been added to "media-type". o Elements "status", "snd-status" and "rcv-status" have been added to "media-type". o Element "dialog-id" has been renamed to "instance". o "Constructing Coherent State" section has been updated to include user and media partial notifications. 12.3 Changes since -03 o "Constructing Coherent State" section has been updated. o In order to support partial notifications, two placeholders "conference-ids" and "policy-ids" (for "conf-uri" and "policy-uri" elements, correspondingly) are created. o Discussion and security considerations regarding anonymous participation have been added. o Optional elements "dialog-uri", "info" and "label" per media stream are added. 12.4 Changes since -02 o State "muted-by-focus" is added to user's status. o Optional conference attribute "recording" is added. o Policy URI placeholder (i.e. element "policy-uri") is created. o Example's syntax is corrected. o Optional attribute "cascaded-focus" URI per user is added. Rosenberg, et al. Expires April 25, 2005 [Page 44] Internet-Draft Conference Package October 2004 o Optional additional conference identifiers (i.e. element "conf-uri") are added. o In order to cover all possible cases, participant's status is expressed using three optional statuses: "status", "joining-mode" and "disconnection-reason". That is instead of "activity-status", "history-status" and "is-on-dial-out-list". 12.5 Changes since -01 o Package parameters are removed. Decision about performing "recursive" membership algorithm is perceived as a focus local policy. o General information (i.e. pointers to additional available services) is removed. The defined XML schema can be extended in future to include those when XCON work matures. o Dialog information is removed. It can be obtained by direct subscription to a dialog package of a participant. o Media stream information is aligned with SDP definitions (media and proto) and SSRC attribute is added. o Participant's status is expressed using two optional statuses: "activity" and "history". Optional "is-on-a-dial-out-list" indication is added. o Normative references to XCON work are removed. o Optional sidebar rosters are added. Rosenberg, et al. Expires April 25, 2005 [Page 45] Internet-Draft Conference Package October 2004 13. References 13.1 Normative References [1] Mealling, M., "The IETF XML Registry", draft-mealling-iana-xmlns-registry-05 (work in progress), June 2003. [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [3] Moats, R., "URN Syntax", RFC 2141, May 1997. [4] Moats, R., "A URN Namespace for IETF Documents", RFC 2648, August 1999. [5] Murata, M., St. Laurent, S. and D. Kohn, "XML Media Types", RFC 3023, January 2001. [6] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002. [7] Roach, A., "Session Initiation Protocol (SIP)-Specific Event Notification", RFC 3265, June 2002. [8] Peterson, J., "A Privacy Mechanism for the Session Initiation Protocol (SIP)", RFC 3323, November 2002. [9] Camarillo, G., Eriksson, G., Holler, J. and H. Schulzrinne, "Grouping of Media Lines in the Session Description Protocol (SDP)", RFC 3388, December 2002. [10] Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", STD 64, RFC 3550, July 2003. 13.2 Informative References [11] Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming Protocol (RTSP)", RFC 2326, April 1998. [12] Handley, M. and V. Jacobson, "SDP: Session Description Protocol", RFC 2327, April 1998. [13] Vaha-Sipila, A., "URLs for Telephone Calls", RFC 2806, April 2000. Rosenberg, et al. Expires April 25, 2005 [Page 46] Internet-Draft Conference Package October 2004 [14] Levin, O., "H.323 Uniform Resource Locator (URL) Scheme Registration", RFC 3508, April 2003. [15] Rosenberg, J., "A Framework for Conferencing with the Session Initiation Protocol", draft-ietf-sipping-conferencing-framework-03 (work in progress), October 2004. [16] Rosenberg, J. and H. Schulzrinne, "An INVITE Inititiated Dialog Event Package for the Session Initiation Protocol (SIP)", draft-ietf-sipping-dialog-package-04 (work in progress), February 2004. [17] Koskelainen, P. and H. Khartabil, "Requirements for Conference Policy Control Protocol", draft-ietf-xcon-cpcp-reqs-04 (work in progress), August 2004. [18] Rosenberg, J., "Obtaining and Using Globally Routable User Agent (UA) URIs (GRUU) in the Session Initiation Protocol (SIP)", draft-ietf-sip-gruu-02 (work in progress), July 2004. [19] Levin, O. and G. Camarillo, "The SDP (Session Description Protocol) Label Attribute", draft-ietf-mmusic-sdp-media-label-00 (work in progress), September 2004. Authors' Addresses Jonathan Rosenberg dynamicsoft 600 Lanidex Plaza Parsippany, NJ 07054 US Phone: +1 973 952-5000 EMail: jdrosen@dynamicsoft.com URI: http://www.jdrosen.net Rosenberg, et al. Expires April 25, 2005 [Page 47] Internet-Draft Conference Package October 2004 Henning Schulzrinne Columbia University M/S 0401 1214 Amsterdam Ave. New York, NY 10027 US EMail: schulzrinne@cs.columbia.edu URI: http://www.cs.columbia.edu/~hgs Orit Levin (editor) Microsoft Corporation One Microsoft Way Redmond, WA 98052 USA EMail: oritl@microsoft.com Rosenberg, et al. Expires April 25, 2005 [Page 48] Internet-Draft Conference Package October 2004 Intellectual Property Statement 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 this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Rosenberg, et al. Expires April 25, 2005 [Page 49]