SIPREC P. Kyzivat
Internet-Draft M. Yan
Intended status: Informational Huawei
Expires: March 17, 2014 S. Romano
University of Napoli
September 13, 2013
Multimedia Conference Recording Use Cases and Requirements
draft-kyzivat-siprec-conference-use-cases-00
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 functionalities 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.
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."
This Internet-Draft will expire on March 17, 2014.
Kyzivat, et al. Expires March 17, 2014 [Page 1]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
Copyright Notice
Copyright (c) 2013 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. 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 . . . . . . . . . . . . . . . . 6
4.7. Multimedia Conference Recording . . . . . . . . . . . . . 6
5. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. REQ-001 . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. REQ-002 . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.3. REQ-003 . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.4. REQ-004 . . . . . . . . . . . . . . . . . . . . . . . . . 7
5.5. REQ-005 . . . . . . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . . . . . . 8
8.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
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
and presentation graphics [RFC4597]. These extended channels
recording have the same strong needs as audio or video, especially in
Kyzivat, et al. Expires March 17, 2014 [Page 2]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
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,
shared data and even floor negotiation information via BFCP. Such an
exhaustive reconstruction could give audiences more information and a
better experience.
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 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 conference. 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, DTMF, video, 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 session is one of key cases about the IM session in
CS of 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.
The host and participants in conference might start MSRP sessions
among each others 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 a special RS channel. The replicated content could be the
Message/CPIM message that contains text, HTML and Image, etc.
Recording XMPP based IM in CS is out of the scope for this document.
The data sharing, known as content sharing or content streams as
well, in a multimedia conference's CS has functionalities as screen
sharing, application sharing, document sharing, etc. These data
streams of them could be managed as still images (snapshots with
increments) or as dynamic streams (video streams) to carry details
like slide presentation, annotating, 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 codec by application on peer's client or turned from multiple
screenshots, or even the still images carried by MSRP channels.
Kyzivat, et al. Expires March 17, 2014 [Page 3]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
One way for a conference focus 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 to 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 session 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 "media stream" for data sharing,
distinct from the main video streams, with different m-lines or
metadata. There is also need of a mechanism for the SRC to bound the
number of media streams to be recorded, especially when the
participant number in a conference is extremely large.
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 of
special case.
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 a whole screen.
Document Sharing: document sharing is the sharing to help multiple
users working simultaneously on a single document or file to achieve
a single final version. It is also called as file sharing or
document collabration.
Kyzivat, et al. Expires March 17, 2014 [Page 4]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
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 followed 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 include any combination of different media types such as
audio, video, text, interactive text, or presentation graphics
[RFC4597].
4. Use cases
4.1. Instant Message Stream Recording
Use Case 1: Instant Message Stream Recording.
Instant message is the function offered to chat between/among peers.
There are page mode and session mode [RFC6914]. Here especially
means the instant message session happened in the point to point call
using session mode, which consider instant message 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.
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 session for security check.
Another example is the remote education training, it need to record
the screen to keep the integrality of training class.
Kyzivat, et al. Expires March 17, 2014 [Page 5]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
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.
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.
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 conference would be recorded as one mixed streams or separated
streams by participants. It has been supported by current SIPREC
mechanism.
4.6. Chat Conference Recording
Use Case 6: Chat Conference Recording.
There is another type conference known as multi-user chat conference
or chat-rooms. The chat conference would have participants to chat
or message each other in conference with nicknames and provide
private chat using the Message Session Relay Protocol (MSRP)
[I-D.ietf-simple-chat]. There would have needs to record the chat
content and details like nichnames.
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.
Kyzivat, et al. Expires March 17, 2014 [Page 6]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
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 MSRP stream recording. This
requirement could derive from use case 1,6,7.
5.2. REQ-002
REQ-002: The mechanism MUST support screen sharing stream recording.
This requirement could derive from use case 2,7.
5.3. REQ-003
REQ-004: The mechanism MUST support application sharing stream
recording. This requirement could derive from use case 3,7.
5.4. REQ-004
REQ-003: The mechanism MUST support document sharing stream
recording. This requirement could derive from use case 4,7.
5.5. REQ-005
REQ-005: The mechanism MUST support metadata or SDP to separate the
main video stream to data/content video stream. This requirement
could derive from use case 3,4,5,7.
6. IANA Considerations
This document contains no IANA considerations.
7. Security Considerations
Not explicitly covered in this version.
8. References
Kyzivat, et al. Expires March 17, 2014 [Page 7]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
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-08
(work in progress), May 2013.
[I-D.ietf-siprec-protocol]
Portman, L., Lum, H., Eckel, C., Johnston, A., and A.
Hutton, "Session Recording Protocol", draft-ietf-siprec-
protocol-10 (work in progress), May 2013.
[I-D.ietf-siprec-metadata]
R, R., Ravindran, P., and P. Kyzivat, "Session Initiation
Protocol (SIP) Recording Metadata", draft-ietf-siprec-
metadata-12 (work in progress), May 2013.
[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.
Kyzivat, et al. Expires March 17, 2014 [Page 8]
Internet-Draft Use Cases for Multimedia Conf Rec September 2013
[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.
[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.
[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 March 17, 2014 [Page 9]