[Search] [txt|xml|pdf|bibtex] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02                                                      
SIPREC                                                        P. Kyzivat
Internet-Draft                                                    M. Yan
Intended status: Informational                                    Huawei
Expires: February 5, 2015                                      S. Romano
                                                    University of Napoli
                                                          August 4, 2014


       Multimedia Conference Recording Use Cases and Requirements
              draft-kyzivat-siprec-conference-use-cases-02

Abstract

   The current work of SIPREC will soon finish.  As conferences are the
   key requirement for some environments, it is worth to explore several
   extensions and additional functionality to support multimedia
   conference recording.  SIPREC is not sufficient to record all the
   conference sessions via certain interactive media channels, like
   multi-user chat or screen sharing.

   This draft tries to show the use cases for multimedia conference
   recording and the requirements for how to work well under SIPREC
   mechanism.  The requirements ask for extensions to SIP that will
   manage delivery of RTP media sessions, including content media
   defined by [RFC4796] , and MSRP media sessions to a recording device.
   The recorded media sessions are all SIP-based.

Requirements Language

   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 [RFC2119] .

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   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."




Kyzivat, et al.         Expires February 5, 2015                [Page 1]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   This Internet-Draft will expire on February 5, 2015.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Multimedia Conference Recording Overview  . . . . . . . . . .   3
   3.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Use cases . . . . . . . . . . . . . . . . . . . . . . . . . .   5
     4.1.  MSRP Instant Message Stream Recording . . . . . . . . . .   5
     4.2.  Screen Sharing Stream Recording . . . . . . . . . . . . .   5
     4.3.  Application Sharing Stream Recording  . . . . . . . . . .   6
     4.4.  Document Sharing Stream Recording . . . . . . . . . . . .   6
     4.5.  Audio/Video Conference Recording  . . . . . . . . . . . .   6
     4.6.  Chat Conference Recording . . . . . . . . . . . . . . . .   7
     4.7.  Multimedia conference Recording . . . . . . . . . . . . .   7
   5.  Requirements  . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  REQ-001 . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.2.  REQ-002 . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.3.  REQ-003 . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.4.  REQ-004 . . . . . . . . . . . . . . . . . . . . . . . . .   8
     5.5.  REQ-005 . . . . . . . . . . . . . . . . . . . . . . . . .   8
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   8
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   9
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   In general, a basic video conference has participants with video
   channels, audio channels and DTMF ability.  An advanced multimedia
   conference would have extended channels like text, interactive text



Kyzivat, et al.         Expires February 5, 2015                [Page 2]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   and presentation graphics [RFC4597] . These extended channels
   recording have the same strong needs as audio or video, especially in
   some conference use cases.  The conference's host and participants,
   even nonparticipants, would like to play back the recordings in real-
   time or non-real-time for different purposes, like editing summary,
   reviewing outlines or monitoring process.  The recordings should have
   the ability to reconstruct the conference richly, with adequate media
   and metadata recorded, which are not only audio/video but also IM and
   shared content.  Such an exhaustive reconstruction could give
   audiences more information and a better experience.  The recorded
   sessions can be any RTP media sessions, including the content media
   (as defined by [RFC4796] ) transferred as video stream, and MSRP
   media session which is SIP based media session.

2.  Multimedia Conference Recording Overview

   There is one use case (use case 11) covering the recording of a
   multi-channel and multimedia session in the existing use case
   document [RFC6341] . Aside from audio, video, DTMF (as defined by
   [RFC4733] ) and text (as defined by [RFC4103] ), it does not include
   other interactive channels.  The limitations to the multi-channel
   types leads to poor support for recording multimedia conferences.  A
   multimedia conference has various channels, including audio, video,
   IM, data sharing (screen/document/application), etc.  SIPREC is
   mostly capable of recording any sort of RTP media sessions, including
   voice, video, DTMF (as defined by [RFC4733] ) and text [RFC6341] with
   SDP negotiation [I-D.ietf-siprec-protocol] and certain metadata
   [I-D.ietf-siprec-metadata] . But it is not evident how to support the
   remaining media, like multi-user chat or screen sharing.

   Multi-user chat is one of key cases about the IM session in
   multimedia conference.  A multi-user chat or simple-chat session is
   to handle the media to relay instant messages received from one
   participant to the rest of the participants in the conference
   [I-D.ietf-simple-chat] , especially for the MSRP session which is a
   SIP based system.  The host and participants in a conference might
   start MSRP sessions among each other for public group chat, sidebar
   chat or whisper chat.  These MSRP content could be replicated by SRC
   (might be the MSRP switch or certain MSRP replay or MSRP client) to
   deliver to SRS via special RS channel(s).  The replicated content
   could be the Message/CPIM message that contains text, HTML and
   images, etc.  The document only considers the SIP based system,
   recording XMPP based IM in CS is out of the scope.

   The data sharing session, known as content sharing or content streams
   as well, in a multimedia conference's CS has functionality like
   screen sharing, application sharing, document sharing, etc.  These
   data streams could be managed as still images (snapshots with



Kyzivat, et al.         Expires February 5, 2015                [Page 3]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   increments) or as dynamic streams (video streams) to carry details
   like slide presentation, annotations, direct editing or page turning.
   Especially, the screen sharing would have different ways to get its
   data streams, like the video streams directly offered from VGA port
   or encoded/decoded by an application on peer's client, or turned from
   multiple screenshots, or even the still images carried by MSRP
   channels.

   One way for a conference focus/mixer to record a conference is
   introduced in [I-D.ietf-siprec-architecture] . This defines how the
   conference focus works as a SRC to deliver RTP streams and associate
   recording metadata with SRS.  It may choose the recording RTP stream
   type, separated or mixed.  There are more details about how to use
   SDP, RTP for recording by participant or by media type in
   [I-D.ietf-siprec-protocol] . The focus may setup different recording
   sessions for different media streams recorded separately, or one
   recording session for a mixed media stream created by the SRC, or
   even multiplexing different media streams in a single RTP recording
   session [I-D.ietf-siprec-protocol] .

   But more is needed to support other media streams in a multimedia
   conference.  There is need for MSRP switch/relay/client as SRC to
   replicate MSRP sessions to the recorder, with a new "media stream"
   type in RS for delivering MSRP based streams or contents.  There is
   another need for a new type of metadata to indicate when media
   streams are being used to represent screen/application/data sharing
   sessions, distinct from the main video streams.  There is also need
   of a mechanism for the SRC to bound the number of media streams to be
   recorded, especially when the participants number in a conference is
   extremely large.  The document does not include recording any of the
   extended session attributes being defined by the CLUE WG.

3.  Definitions

   Instant Message Stream: instant message stream refers to the streams
   transferred by messages between users in near real-time [RFC3248] .

   Data Sharing: Data sharing is to use a content channel for
   collaboratively working on documents, files, images, desktops, etc in
   real time.  It is also called as content sharing, including
   application sharing, screen sharing, document sharing, etc.

   Application Sharing: application sharing is the sharing of the
   graphical user-interface of an application amongst multiple users
   simultaneously in real time.  The slide sharing could be one special
   case.





Kyzivat, et al.         Expires February 5, 2015                [Page 4]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   Screen Sharing: screen sharing is the sharing of a computer desktop
   amongst multiple users simultaneously in real time, also called
   desktop sharing.  Comparing to application sharing, which is always a
   single one, screen sharing is for the whole screen.

   Document Sharing: document sharing is the sharing to help multiple
   users work simultaneously on a single document or file to achieve a
   single final version.  It is also called file sharing or document
   collaboration.

   Audio/Video Conference: Audio/video conference is one sort of various
   conferences.  In SIP, an audio/video conference is an instance of a
   multi-party conversation that matches the definition in [RFC4353] and
   the framework in [RFC5239] , with the media channels as audio and
   video.

   Chat Conference: a synonym for a multi-party chat conference
   [I-D.ietf-simple-chat] .

   Multimedia Conference: multimedia conference is the multi-party
   conversation including any combination of different media types such
   as audio, video, text, interactive text, or presentation graphics
   [RFC4597] .

4.  Use cases

4.1.  MSRP Instant Message Stream Recording

   Use Case 1: MSRP Instant Message Stream Recording.

   Instant message is the function offered to chat between/among peers.
   There are page mode and session mode ( MSRP [RFC6914] ).  Here we are
   concerned with instant message sessions in the context of a point to
   point call using session mode, which treats the MSRP instant message
   session as a media type.

   For example, in a call center or emergency (first-responder) center,
   a customer could use the web client to start a chat with an agent
   about his questions or describing the situation happened around him.
   Call center or emergency center would need to record those chat
   sessions between customers and agents.

4.2.  Screen Sharing Stream Recording

   Use Case 2: Screen Sharing Stream Recording.






Kyzivat, et al.         Expires February 5, 2015                [Page 5]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   This is also well known as desktop sharing or remote sharing between
   peers.  This function could be also used in a point to point call
   directly.

   In an enterprise, the softphone calls between colleagues would choose
   screen sharing to illustrate their views clearly if the voice
   discussing is not enough.  The enterprise would ask to record those
   screen sharing sessions for security check.

   Another example is the remote education training, which needs to
   record the screen to keep track of the whole training class.

   The state of the shared screen is recorded as video (and possibly
   audio) media, with metadata indicating that the stream represents
   screen sharing.

4.3.  Application Sharing Stream Recording

   Use Case 3: Application Sharing Stream Recording.

   Users would choose application sharing instead of screen sharing to
   avoid exposing the privacy content on their computer desktop, when
   have the point-to-point call with others or have a conference call.
   And the recorded streams are the content of applications shown in CS.

   The state of the application window is recorded as video (and
   possibly audio) media, with metadata indicating that the stream
   represents application sharing.

4.4.  Document Sharing Stream Recording

   Use Case 4: Document Sharing Stream Recording.

   Users would work on one document simultaneously in real time.  The
   content of document would be recorded (which is close to use case 3).

   The state of the document sharing window is recorded as video media,
   with metadata indicating that the stream represents data sharing.

4.5.  Audio/Video Conference Recording

   Use Case 5: audio/video conference Recording.

   The recording for audio/video conference is basic.  All the channels
   in a conference would be recorded as one mixed stream or as separate
   streams by participants.  It has been supported by current SIPREC
   mechanism.




Kyzivat, et al.         Expires February 5, 2015                [Page 6]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


4.6.  Chat Conference Recording

   Use Case 6: chat conference Recording.

   There is another Conference type, known as multi-user chat conference
   or chat-rooms.  The chat conference would have participants in a
   conference to chat or text each other with nicknames and provide
   private chat using the Message Session Relay Protocol (MSRP)
   [I-D.ietf-simple-chat] . In this case, there would be a need to
   record the chat content and details like nicknames.

4.7.  Multimedia conference Recording

   Use Case 7: Multimedia conference Recording.

   This is a special use case to indicate the multimedia conference
   recording environment.  When there is a common education class or
   skill training conference, the audiences who are not in the
   conference session would prefer replaying the conference in real-time
   with professor or lecturer's voice with their slides, better include
   the video of if available.  The recording of this education
   conferences need to record audio, video from hosts and data sharing
   of theirs.

   While the audiences(out-conference) need to know what the
   audiences(in-conference) feedback to the training, they might also
   want to know what those audiences(in-conference) have been discussing
   in IM session.  Thus the recording need record the IM sessions.

5.  Requirements

5.1.  REQ-001

   REQ-001: The mechanism MUST support recording of MSRP media sessions.
   This requirement derives from use cases 1,6,7.

5.2.  REQ-002

   REQ-002: The mechanism MUST support recording of screen sharing using
   audio and video media.  This requirement derives from use cases 2,7.

5.3.  REQ-003

   REQ-004: The mechanism MUST support recording of application sharing
   using audio and video.  This requirement derives from use cases 3,7.






Kyzivat, et al.         Expires February 5, 2015                [Page 7]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


5.4.  REQ-004

   REQ-003: The mechanism MUST support recording of document sharing
   using video media.  This requirement derives from use cases 4,7.

5.5.  REQ-005

   REQ-005: The mechanism MUST support metadata or SDP to identify media
   streams used to record screen/application/document sharing.  This
   requirement derives from use cases 2,3,4,7.

6.  IANA Considerations

   This document contains no IANA considerations.

7.  Security Considerations

   Not explicitly covered in this version.

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3261]  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.

   [RFC6341]  Rehor, K., Portman, L., Hutton, A., and R. Jain, "Use
              Cases and Requirements for SIP-Based Media Recording
              (SIPREC)", RFC 6341, August 2011.

   [I-D.ietf-siprec-architecture]
              Hutton, A., Portman, L., Jain, R., and K. Rehor, "An
              Architecture for Media Recording using the Session
              Initiation Protocol", draft-ietf-siprec-architecture-12
              (work in progress), February 2014.

   [I-D.ietf-siprec-protocol]
              Portman, L., Lum, H., Eckel, C., Johnston, A., and A.
              Hutton, "Session Recording Protocol", draft-ietf-siprec-
              protocol-13 (work in progress), July 2014.






Kyzivat, et al.         Expires February 5, 2015                [Page 8]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   [I-D.ietf-siprec-metadata]
              R, R., Ravindran, P., and P. Kyzivat, "Session Initiation
              Protocol (SIP) Recording Metadata", draft-ietf-siprec-
              metadata-15 (work in progress), February 2014.

   [I-D.kyzivat-siprec-webconf-use-case]
              Kyzivat, P. and M. Yan, "Web Conference Recording Use
              Case", draft-kyzivat-siprec-webconf-use-case-00 (work in
              progress), May 2013.

   [I-D.ietf-simple-chat]
              Niemi, A., Garcia, M., and G. Sandbakken, "Multi-party
              Chat Using the Message Session Relay Protocol (MSRP)",
              draft-ietf-simple-chat-18 (work in progress), January
              2013.

8.2.  Informative References

   [RFC3248]  Armitage, G., Carpenter, B., Casati, A., Crowcroft, J.,
              Halpern, J., Kumar, B., and J. Schnizlein, "A Delay Bound
              alternative revision of RFC 2598", RFC 3248, March 2002.

   [RFC4103]  Hellstrom, G. and P. Jones, "RTP Payload for Text
              Conversation", RFC 4103, June 2005.

   [RFC4353]  Rosenberg, J., "A Framework for Conferencing with the
              Session Initiation Protocol (SIP)", RFC 4353, February
              2006.

   [RFC4597]  Even, R. and N. Ismail, "Conferencing Scenarios", RFC
              4597, August 2006.

   [RFC4733]  Schulzrinne, H. and T. Taylor, "RTP Payload for DTMF
              Digits, Telephony Tones, and Telephony Signals", RFC 4733,
              December 2006.

   [RFC4796]  Hautakorpi, J. and G. Camarillo, "The Session Description
              Protocol (SDP) Content Attribute", RFC 4796, February
              2007.

   [RFC4975]  Campbell, B., Mahy, R., and C. Jennings, "The Message
              Session Relay Protocol (MSRP)", RFC 4975, September 2007.

   [RFC5239]  Barnes, M., Boulton, C., and O. Levin, "A Framework for
              Centralized Conferencing", RFC 5239, June 2008.






Kyzivat, et al.         Expires February 5, 2015                [Page 9]


Internet-Draft      Use Cases for Multimedia Conf Rec        August 2014


   [RFC6914]  Rosenberg, J., "SIMPLE Made Simple: An Overview of the
              IETF Specifications for Instant Messaging and Presence
              Using the Session Initiation Protocol (SIP)", RFC 6914,
              April 2013.

Authors' Addresses

   Paul H. Kyzivat
   Huawei

   Email: pkyzivat@alum.mit.edu


   Michael Yan
   Huawei

   Email: michael.yan@huawei.com


   Simon Pietro Romano
   University of Napoli

   Email: spromano@unina.it




























Kyzivat, et al.         Expires February 5, 2015               [Page 10]