Transport Area P. Koskelainen Internet-Draft Nokia Expires: December 22, 2003 June 23, 2003 Requirements for Conference Policy Control Protocol draft-koskelainen-xcon-cpcp-reqs-00 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 22, 2003. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract The conference policy server allows clients to manipulate and interact with the conference policy. One mechanism to manipulate the policy is to use conference policy control protocol (CPCP). This document gives the requirements for CPCP. Koskelainen Expires December 22, 2003 [Page 1] Internet-Draft CPCP-req June 2003 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions Used in This Document . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Integration with Floor Control . . . . . . . . . . . . . . . . 6 5. Conference Policy Data Model . . . . . . . . . . . . . . . . . 7 6. CPCP Requirements . . . . . . . . . . . . . . . . . . . . . . 8 6.1 Conference creation, termination and joining . . . . . . . . . 8 6.2 Manipulating general conference attributes . . . . . . . . . . 8 6.3 Authentication and Security . . . . . . . . . . . . . . . . . 9 6.4 Application and media manipulation . . . . . . . . . . . . . . 9 6.5 ACL manipulation . . . . . . . . . . . . . . . . . . . . . . . 9 6.6 Floor control . . . . . . . . . . . . . . . . . . . . . . . . 10 6.7 Inviting and ejecting users . . . . . . . . . . . . . . . . . 10 6.8 User Privileges . . . . . . . . . . . . . . . . . . . . . . . 10 6.9 General Protocol Requirements . . . . . . . . . . . . . . . . 11 7. Notifications and Subscriptions . . . . . . . . . . . . . . . 12 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 Normative References . . . . . . . . . . . . . . . . . . . . . 14 Informative References . . . . . . . . . . . . . . . . . . . . 15 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 15 Intellectual Property and Copyright Statements . . . . . . . . 16 Koskelainen Expires December 22, 2003 [Page 2] Internet-Draft CPCP-req June 2003 1. Introduction The conferencing framework document [3] describes the overall architecture, terminology, and protocol components needed for multi- party conferencing. It defines a logical function called a conference policy server (CPS) which can store and manipulate rules associated with participation in a conference. These rules include directives on the lifespan of the conference, who can and cannot join the conference, definitions of roles available in the conference and the responsibilities associated with those roles, and policies on who is allowed to request which roles. The conference policy control protocol (CPCP) is a client-server protocol that can be used by users to manipulate the rules associated with the conference. The conference policy is represented by a URI. There is a unique conference policy for each conference. The conference policy URI points to a conference policy server which can manipulate that conference policy. Conferencing framework describes also conference notification service that is a logical function provided by the focus. It means that the focus can act as a notifier, accepting subscriptions to the conference state. Note that CPCP is not the only mechanism to manipulate conference policy, but other mechanisms exists as well, such as Web interface. This document can be used with other documents, such as Conferencing framework document [3]. Moreover, [4] and [6] give useful background information about conferencing and floor control. Koskelainen Expires December 22, 2003 [Page 3] Internet-Draft CPCP-req June 2003 2. Conventions Used in This Document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Koskelainen Expires December 22, 2003 [Page 4] Internet-Draft CPCP-req June 2003 3. Terminology This document uses the definitions from [3]. Additional definitions: ACL Access control list (ACL) defines users who can join to a conference. Users may have allow, blocked or pending status in the list. Each conference has its own ACL. Moderator A special (privileged) role for a user that is allowed to manipulate conference policy and override policy decisions made by other users. Floor control Floor control is a mechanism that enables applications or users to gain safe and mutually exclusive or non-exclusive access to the shared object or resource in a conference. Privilege A privilege is a right to perform a manipulation operation for a conference. It is user permission such as "MODIFY ACL", "TERMINATE CONFERENCE", "INVITE USERS", "EJECT USERS", "MODIFY FLOOR POLICY", "MODIFY MEDIA POLICY", "HAND OFF A PRIVILEGE TO ANOTHER USER" (assuming that privileges are individual instead of group based e.g. senior-members have all privileges) Koskelainen Expires December 22, 2003 [Page 5] Internet-Draft CPCP-req June 2003 4. Integration with Floor Control Floor control is an optional feature often used by conferencing applications. It enables applications or users to gain safe and mutually exclusive or non-exclusive input access to a shared object or resource. We define a floor as the temporary permission for a conference participant to access or manipulate a specific shared resource or group of resources. We assume that the ability of users to create floors is governed by the conference policy. Privileged conference user may use floor control protocol (see e.g. [5]) or some other mechanism to create floors. The conference policy defines who is allowed to create, change, and remove floors using the floor control protocol. Floor chair is also appointed using the floor control protocol when the floor is created. Typically, only conference moderators are allowed to use these commands. The conference moderator can remove the floor at any time using floor control protocol (so that the resources are no longer floor- controlled), or change the floor chair or the floor parameters. The floor chair just controls the access to the floor, according to the floor policy, defined at a time when the floor is created. Koskelainen Expires December 22, 2003 [Page 6] Internet-Draft CPCP-req June 2003 5. Conference Policy Data Model Conference policy data is relative static. It is not updated frequently as e.g. participant list is not part of conference policy. Users with sufficient privileges are able to manipulate conference policy. For example, a user with sufficient privileges may manipulate conference's access control list by adding a user into the ACL white list. Koskelainen Expires December 22, 2003 [Page 7] Internet-Draft CPCP-req June 2003 6. CPCP Requirements This section describes conference policy requirements. 6.1 Conference creation, termination and joining REQ-A1: It MUST be possible to create a new conference at focus, resulting in a URI. REQ-A2: It MUST be possible to associate policy attributes to a conference URI. REQ-A3: It MUST be possible to reserve a conference URI from the focus for future use with or without associating policy attributes to it. REQ-A4: It MUST be possible for a user to fetch some or all components of the conference policy for a given conference URI, during and before joining the conference. REQ-A5: It MUST be possible to delete the existing conference URI and release all resources associated with it. REQ-A6: It SHOULD be possible to join anonymously to the conference and still be able to send and receive data and private 1-to-1 SIP messages anonymously. 6.2 Manipulating general conference attributes REQ-B2: It MUST be possible to set and modify conference Subject that can be seen e.g. in web page, SDP s line or SIP Subject header. REQ-B3: It MUST be possible to set, modify and delete conference URI display name. REQ-B4: It MUST be possible to set, modify and delete conference creator information (as is seen e.g. in SDP o line). REQ-B5: It MUST be possible to set, modify and delete conference URI link for more information (as used e.g. in SDP u line). REQ-B6: It MUST be possible to set, modify and delete conference host contact information (as used e.g. in SDP e and p lines). REQ-B7: It MUST be possible to set, modify and delete short conference session description (as used e.g. in SDP i line). This can be per session or per media. Koskelainen Expires December 22, 2003 [Page 8] Internet-Draft CPCP-req June 2003 REQ-B8: It MAY be possible to set, modify and delete the parameter for max number of conference participants. This defines how many users at max can be present at the same time. OPEN ISSUE: This is typical parameter in PSTN conferences, but does this make sense in IP world (and with different codecs) ? REQ-B9: It MUST be possible to set whether the conference is public or hidden (if hidden, focus does not return description to outsiders for OPTIONS or other requests). REQ-B10: Conference policy MUST have an attribute that defines whether the conference is active or inactive. (If active, users can join etc). [This is needed if start/end times are not used] REQ-B11: It MUST be possible to give the list of invited users into the conference (dial-out case). REQ-B-12: It MUST be possible to set, modify and delete conference Keywords. (This may be useful e.g. for search engines). 6.3 Authentication and Security REQ-C1: It MUST be possible to define the authentication mechanism, and passwords for user joins. REQ-C2: It MUST be possible to use sips: scheme as a conference URI. REQ-C3: It MUST be possible to define encryption keys for media data. [OPEN ISSUE: Does this belong to media policy?] 6.4 Application and media manipulation REQ-D1: It MUST be possible to assign and de-assign the users who are allowed to manipulate media policy. 6.5 ACL manipulation REQ-E1: It MUST be possible to add and delete users into and from ACL white list (allowed to join), ACL black list (not allowed to join) and ACL pending list (further authorization needed). REQ-E2: ACL conflicts MUST be solved in a well-defined way (e.g. what if user appears both in black list and in white list) e.g. by mandating the order in which ACL definitions are evaluated (e.g. most specific expression first). REQ-E3: It MUST be possible to use wildcards in user part in ACL Koskelainen Expires December 22, 2003 [Page 9] Internet-Draft CPCP-req June 2003 (such as sip:*@example.com in white list). REQ-E4: It MUST be possible to allow and disallow anonymous and hidden joins to the conference. REQ-E5: ACL MUST have default policy for those users that no matching rule is found. 6.6 Floor control REQ-F1: It MUST be possible to assign and de-assign the users who are allowed to manipulate floor policy. 6.7 Inviting and ejecting users REQ-G1: It MUST be possible to invite one or more users into the conference (including so called "mass invitation" operation). REQ-G2: It MUST be possible eject one or more users from the conference (including so called "mass ejection" operation). 6.8 User Privileges REQ-H1: It MUST be possible to give a privilege to a user. (A privilege may be operation, such as right to expel, right to modify conference ACL, right to hand off all or some privileges to another user). REQ-H2: It MUST be possible to remove a privilege from a user. REQ-H3: It MAY be possible to support user privilege groups (e.g. senior-members) and to group privileges together, such as senior-members can eject users and manipulate ACL. REQ-H4: It MAY be possible that default privileges (e.g. only the creator can delete conference) are defined by the Conference Policy Control Protocol that can be changed by the conference policy. REQ-H5: It MUST be possible to authorize users who have the right to subscribe to specific events, such as ACL changes. REQ-H6: It MAY be possible request new privileges from the conference policy server via CPCP. REQ-H7: It SHOULD be possible to define who is allowed to subscribe to conference related events. REQ-H8: It MAY be possible that default privileges are defined for Koskelainen Expires December 22, 2003 [Page 10] Internet-Draft CPCP-req June 2003 new conference, such as conference creator has all privileges available and others do not have have any of them. 6.9 General Protocol Requirements REQ-CP-1: Protocol behaviour: CPCP protocol SHOULD be a reliable client-server protocol. Hence, it SHOULD have a positive response indicating that the request has been received, or error response if an error has occurred. The sending UA takes care of retransmission in the case of packet loss. REQ-CP-2: Manipulations of the policy collection MUST exhibit the ACID property; that is, they MUST be atomic, be consistent, durable, and operate independently. REQ-CP-3: It MAY be possible for the client to batch multiple operations (such as add a user to ACL black list, or remove a user from ACL white list) into a single request that is processed atomically. REQ-CP-4: It MUST be possible for the server to authenticate the client. REQ-CP-5: It MUST be possible for the client to authenticate the server. REQ-CP-6: It MUST be possible for message integrity to be ensured between the client and the server. REQ-CP-7: It MUST be possible for privacy to be ensured between the client and server. Koskelainen Expires December 22, 2003 [Page 11] Internet-Draft CPCP-req June 2003 7. Notifications and Subscriptions It is necessary to have a notification mechanism in addition to CPCP, e.g. SIP. For example, conference owner (or a user with sufficient privileges) may subscribe to the conference management event, and get notified when there is a need to do policy manipulation, such as ACL manipulation for on-going join attempt. It is also necessary to authenticate who is allowed to subscribe to these events. Koskelainen Expires December 22, 2003 [Page 12] Internet-Draft CPCP-req June 2003 8. Acknowledgements The author would like to thank Eric Burger, Xiaotao Wu, Henning Schulzrinne, Simo Veikkolainen and IETF conferencing design team for their feedback. Koskelainen Expires December 22, 2003 [Page 13] Internet-Draft CPCP-req June 2003 Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, BCD 14, March 1997. [2] Rosenberg et al., J., "SIP: Session Initiation Protocol", RFC 3261, June 2002. [3] Rosenberg, J., "A Framework for Conferencing with the Session Initiation Protocol", draft-rosenberg-sipping-conferencing-framework-01 (work in progress), February 2003. Koskelainen Expires December 22, 2003 [Page 14] Internet-Draft CPCP-req June 2003 Informative References [4] Koskelainen, P., Schulzrinne, H. and X. Wu, "Additional Requirements to Conferencing", October 2002. [5] Wu, X., Schulzrinne, H. and P. Koskelainen, "Use of SIP and SOAP for conference floor control", January 2003. [6] Koskelainen, P., Schulzrinne, H. and X. Wu, "A sip-based conference control framework", Nossdav'2002 Miami Beach, May 2002. Author's Address Petri Koskelainen Nokia P.O. Box 100 (Visiokatu 1) Tampere FIN-33721 Finland EMail: petri.koskelainen@nokia.com Koskelainen Expires December 22, 2003 [Page 15] Internet-Draft CPCP-req June 2003 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property 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; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. 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