A Standard Framework for Content Adaptation: MediaCtrl

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1 A Standard Framework for Content Adaptation: MediaCtrl Lorenzo Miniero (CINI-UoN) The Italian CONTENT Local Industry Workshop Napoli, 29 th May

2 Overview Issues Heterogeneous Networks Heterogeneous Devices Encoding/Decoding/Bandwidth Protocol Requirements Signaling of Media Session Media Delivery Control and Interactivity Standardization efforts Third Generation Parthership Project (3GPP) Internet Engineering Task Force (IETF) 2

3 Challenge 3

4 Issues Heterogeneous networks and devices Bandwidth fluctuates Not the same bandwidth anywhere Even if it is, devices may have different capabilities Dynamic behaviour Different codecs/resolutions/etc. Content adaptation QoS feedback mechanisms New Trends Distributed content Need for interactivity Choosing content Controlling media... 4

5 Signaling Session Initiation Protocol (SIP) IETF RFC 3261 ( Negotiates media sessions Originally conceived for VoIP only Subsequently extended to implement any kind of multimedia application Has ways to dinamically update sessions Session Description Protocol (SDP) IETF RFC 3264 ( Conveyed in SIP payloads Provides details about media sessions to negotiate Transport addresses Encoding/direction of media streams SIP/SDP base protocol for IMS IP Multimedia Subsystem (3GPP) Unified access to services from heterogeneous networks 5

6 Media Delivery Real-Time Transport Protocol (RTP) IETF RFC 3550 ( Transports media frames in real-time Opaque to the encoding Negotiated in SIP/SDP messages Real-Time Transport Control Protocol (RTCP) Sister protocol of RTP Provides feedback on delivery of streams Base for QoS mechanisms RTP Payload for DTMF Digits IETF RFC 2833 ( Further means for interactivity DTMF digits can be associated with actions 6

7 Convergent Applications SIP/SDP and RTP/RTCP provide means for end-toend communication Need for an additional control layer with business logic Several protocols can be involved SIP, RTP, HTTP,??? Separation of responsibilities Application Server (Business Logic) Media Server (Content Manipulation and Delivery) AS and MS need a way to interact Media Server Control (IETF MediaCtrl) Standard Framework for Content Adaptation Describes architecture and protocols for [UAs-]AS-MS interaction CINI/UoN deeply involved in standardization process 7

8 SIP Media Server Control (MediaCtrl) Functionality Media Processing Mixing/Transcoding Playing/Recording Storing/Retrieving Detecting Tones (DTMF) Interactive Voice Response (IVR)/VoiceXML Text-to-Speech/Speech Recognition RTP Streams Manipulation Monitoring and Auditing Event Notification (subscription mechanism) SIP SIP MRFC/MRFP (interface/container) in IMS May wrap different specification (e.g. H.248) RTP Application Server Media Server Control Channel RTP Client B 8

9 Why MediaCtrl? Several extant protocols... ITU H (MeGaCo) RFC 4240 MSCML (Media Server Control Markup Language) VoiceXML/CCXML a SIP-aware standard was needed Completely SIP-based Specific requirements (e.g. MRF...) Simpler to work with JSR 309 and SIP Servlets Media Server Control (MEDIACTRL) BOF (Birds of a Feather) in November 2006 Work almost completed 9

Overview Charter http://www.ietf.org/html.charters/mediactrl-charter.

10 Overview Charter Advanced services Content Delivery Interactive Voice Response (IVR) Mixing/Bridging (Conferencing) Several topologies: 1:1 m:n Media Resource Broker Modular approach Header Payload Opaque payloads Control packages Header Payload Transactions as bricks Protocol Messages Control Package 1 Control Package 2 Control Package 3 10

11 Architecture (1) User Signaling (e.g. SIP) Application Server SIP (Media Dialog) SIP (Control Dialog) TCP/TLS (Control Channel) User Agent RTP/SRTP Media Server 11

12 Architecture (2) AS uses SIP to establish TCP/TLS connection to MS SIP dialog called Control Dialog TCP/TLS connection called Control Channel Channel setup: SIP with COMEDIA negotiation Authentication: SYNC message Application Server Frontend for UA signalling SIP 3rd Party Call Control (Media Dialog towards MS) Handles business logic and control layer (e.g. HTTP) Media Server Termination of Media Channels Enforces directives coming from AS and notifies about events AS and RTCP as QoS mechanisms 12

13 Interactive Content Delivery Passive streaming Playout of pre-recorded multimedia files Playout of live multimedia streams (e.g. RTSP) Optional VCR controls (rw, ffw, play, pause, volume, etc.) Interactivity Active Streaming Use of hidden conferences to broadcast source Storing of multimedia contents for future use Voice mail Video messages Tutorials Optimized Delivery MS can fetch content to delivery from any source MS in use can be changed dynamically Media Resource Brokering (MRB) 13

14 Media Resource Brokering (MRB) Generic topology is m:n Several Application Servers (m) and a pool of Media Servers (n) Media Resource Broker Allows AS to audit pool of MS for capabilities/resources MS themselves provide MRB with information MRB tells AS which MS is best according to requirements Required functionality Required encodings Geographic locations... UAs can be moved dynamically from a MS to another Two different interfaces Publisher Interface (MS MRB) Consumer Interface (MRB AS) 14

15 CINI-UoN involvement in MediaCtrl draft-ietf-mediactrl-architecture-04 Design Team draft-ietf-mediactrl-ivr-control-package-06 Design Team draft-ietf-mediactrl-ivr-control-package-06 Design Team draft-ietf-mediactrl-call-flows-00 A. Amirante, T. Castaldi, L. Miniero, S.P.Romano draft-ietf-mediactrl-mrb-00 C. Boulton, L. Miniero Open source prototype implementation

16 MediaCtrl in action 16

17 MediaCtrl in action 17

18 MediaCtrl in action 18

19 Thanks for your attention! 19

20 Acknowledgements 20

Lecture 14: Multimedia Communications

Lecture 14: Multimedia Communications Prof. Shervin Shirmohammadi SITE, University of Ottawa Fall 2005 CEG 4183 14-1 Multimedia Characteristics Bandwidth Media has natural bitrate, not very flexible. Packet