Standard approaches and a case study Corso di Sistemi Multimediali - PowerPoint PPT Presentation

Standard approaches and a case study Corso di Sistemi Multimediali Corso di Applicazioni Telematiche A.A. 2010-11 A.A. 2010-11 Prof. Antonio Picariello Prof. Simon Pietro Romano Università degli Studi di Napoli Federico II Facoltà di Ingegneria 9/6/2011 1

Outline  Web Conferencing Introduction  History and technologies  IETF standardization efforts  Milestones and ongoing works in the RAI area  Centralized Conferencing, Media Control, Session Recording, Via-browserconferencing, Telepresence Systems  From theory to practice: the Meetecho platform  A fully-fledged standard conferencing system made in unina 2

A “Web Conferencing ” definition  The term “Conference” can be used to describe any meeting of people that “confer” about a certain topic  “Web Conferencing” is used to conduct live meetings or presentations over the Internet 3

Features  VoIP (Voice over IP)  Live video  Text chat  Slide presentations  Whiteboard with annotation  Screen/desktop sharing  Application sharing  Recording  Polls and surveys 4

History  Tele-Conferencing  Conference calls (Audio Tele-Conferencing)  Video conferences (Video Tele-Conferencing)  IP-Conferencing  Text Conferencing  Audio and Video Conferencing  Data Conferencing 5

Audio and Video Conferencing Evolution  Analog Phone Lines (PSTN)  Conference calls  Three-way calling  Conference bridges  Video Telephony  Digital Telephony (ISDN)  ITU-T H.320 umbrella recommendation  Next-Generation Networks & VoIP technologies 6

VoIP protocols  SIP – Session Initiation Protocol, RFC 3261  Call signalling  Session intitiation, managing and termination  Codec negotiation  SDP – Session Description Protocol, RFC 4566  Session media stream description  RTP – Real-time Transport Protocol, RFC3550  Media streams transfer 7

Text Conferencing Evolution  Asynchronous Meetings  Posted text messages (not live)  Message/Bulletin Boards  Forums  Network Newsgroups/Mailing lists  Synchronous Meetings  Live text communication  Internet Relay Chat (IRC)  Web-based Chat (CGI/Java)  Instant Messaging (Skype/MSN/XMPP/etc.) 8

Typical scenarios C  From Point-to-Point Calls to Multipoint Calls A+B+C  Three-way calling A+B A B  Coaching scenario  Lecture-mode Conferences  Presentation  Question & Answers session  Ad-hoc and Reserved Conferences  Conference-aware/-unaware participants  Manage conference/users/media/policies  Sidebars/Whispers 9

Issues Server Client A Client B  Call signalling H . 3 2 3 S I P  Gateway functionality  Control and Management  Tone detection (DTMF)  Dedicated protocols Client A Client C Server B A+B  Mixing and Transcoding M e d i a C M e d i a A A  Terminal capabilities Media B A B  User media profiling  Coaching scenario  Videoswitching Client B 10

Standardization Efforts  Geographically dispersed businesses, the rising cost of energy, and the development of NGN lead to the proliferation of proprietary conferencing solutions  No standardization for many years  Lack of interoperability  Platform dependency  Security issues  Cost  Market segmentation  Standardization Bodies  ITU ( International Telecommunication Union )  3GPP ( 3rd Generation Partnership Project )  IETF ( Internet Engineering Task Force ) 11

Standardization Efforts: ITU  Established to standardize and regulate international radio and telecommunications  International Standards referred to as “Recommendations”  ITU-T: Telecommunication Sector  G : Transmission Systems and Media  G.71x (Audio compression, mu-law and a-law)  G.72x (Audio compression, ADPCM)  H : Audiovisual and Multimedia Systems  H.320 (PSTN/ISDN, Telephone Systems)  H.323 (IP, Packet-based Communication Systems)  T : Terminals for Telematic Services  T.120 (Data Sharing Protocols)  T.140 (RTP Interactive Text) 12

Standardization Efforts: IETF  Under the umbrella of the Internet Society  Develops and promotes Internet Standards  Deals in particular with standards of the TCP/IP suite  Organization  Working Groups (WG)  Internet Drafts  Requests for Comments (RFC)  “Rough consensus, running code”  We will focus on some RAI area activities... 13

IETF RAI area  RAI – Real time Applications and Infrastructure  “ Legacy ” standards  Standard VoIP protocols  SIPPING  XCON  MediaCtrl  Brand-new standardization activities  SIPREC  RTCWEB  CLUE 14

SIPPING Working Group  S ession I nitiation P rotocol P roposal IN vesti G ation  Documents the use of SIP for several applications related to telephony and multimedia  SIP Conferencing Models Loosely-Coupled Conference Fully Distributed Tightly-Coupled Conference Multiparty Conference Main actors: - Participants - Focus Sip Conferencing - Mixer - Policy Server Framework - Notification Server 15

XCON Working Group  Centralized Conferencing (“X”CON)  A star topology on the signalling plane  Advanced conferencing features  VoIP + video & data sharing  “ Signalling-agnostic ”  Not only SIP  H.323, IAX, …  Defines :  Conference data model and lifecycle  A suite of client-server protocols to realize sophisticated conferencing scenarios 16

Conference Object &Data Model Template <conference-info> conference object (blueprint) <conference-description> cloning <host-info> creation <conference-state> Registered conference object delete <users> first last join <floor-information> leave <sidebars-by-val> Active delete <sidebars-by-ref> conference object 17

Conference object example <inf nfo:c :con onfer eren ence-in info entity="8773158"> <in info fo:co conf nfere renc nce-des escri ripti tion on> <info:display-text>My Full-Media Conf</info:display-text> <info:conf-uris> <info:entry> <info:uri>xcon:8773158@meetecho.com</info:uri> <xcon:conference-password>3903/0</xcon:conference-password> </info:entry> Conference ID </info:conf-uris>  <info:available-media> Title <info:entry label="audioLabel">  <info:type>audio</info:type> Conference state </info:entry>  <info:entry label="videoLabel"> Password / PIN <info:type>video</info:type>  </info:entry> Allowed join modality </info:available-media>  </ </inf nfo:c :con onfer eren ence-de descr cript ptio ion> Floor handling policy <in info fo:co conf nfere renc nce-sta tate> e>  <info:active>false</info:active> Participants info </inf </ nfo:c :con onfer eren ence-st state te>  <in info fo:us user ers> User ID <info:user entity="13">  <info:display-text>alex</info:display-text> Nickname <info:endpoint entity="sip:alex@130.129.20.143:5060"/>  </info:user> Signalling URI <info:user entity="14">  <info:display-text>user134</info:display-text> Floor info  <info:endpoint entity="sip:user134@39.7.138.42:5080"/> </info:user> Floor ID <xcon:join-handling>allow</xcon:join-handling>  </inf </ nfo:u :use sers> Associated media  <xc xcon on:fl floo oor-inf nform rmat ation on> <xcon:floor-request-handling>confirm</xcon:floor-request-handling> Moderator ID  <xcon:conference-floor-policy> <xcon:floor id="11"> Max number of floor owners  <xcon:media-label>audioLabel</xcon:media-label> <xcon:max-floor-users>8</xcon:max-floor-users> <xcon:moderator-id>13</xcon:moderator-id> </xcon:floor> <xcon:floor id="22"> <xcon:media-label>videoLabel</xcon:media-label> </xcon:floor> </xcon:conference-floor-policy> </xco </ con:flo loor-in infor orma matio ion> 18 </ </in info: o:co confe fere rence ce-info fo>

XCON Protocols  Signalling  SIP, H.323, IAX2, et al.  Floor Control  BFCP (Binary Floor Control Protocol)  Notification  Xcon Event Package  Conference Control  CCMP (Centralized Conferencing Manipulation Protocol)  University of Napoli highly active in this field 19

CCMP – Conference Control  Conference CRUD Manipulation  C reation  From a client-provided model or by cloning system blueprints  R etrieval  U pdate  User profiles, multimedia flow features (audio volume, video layout, …),...  D eletion  XML- based  Carrying datamodel fragments  “Single verb HTTP + CCMP body” transport solution 20

BFCP – Floor Control  Aimed at coordinating access to a set of shared resources  A “Floor” is a token, a temporary permission to access or manipulate a specific shared resource or set of resources  Standardized in RFC 4582  Identifiers (Conferences/Floors/Users)  Floor Control Server  Floor Control Participant  Floor Chair  Negotiation of BFCP connections within SIP/SDP standardized in RFC 4583  Only existing implementation to date: COMICS/Ericsson 21