RADVISION SIP strategy RADVISION is the leading provider of SIP-based technologies SIP protocol stack SIP developer tools (proxy, registrar) RADVISION is pushing for standards Standards for Video Standards for Conferencing Seamless Protocol Integration with providing full support for all of the existing features of our product line RADVISION supports SIP, H.323 (IP), H.320 (ISDN), H.324M (3G)
What Does it Take to Have a Multimedia SIP Conference?
Building Blocks Point-to-Point Call Control Baseline SIP/SDP Point-to-Point Media Control Video SIP Advanced Call Control SIP conferencing extensions (Optional) Refer Method (Optional) Conference Control Participants Control Floor Control (Optional)
Point-to-Point Basic Media Description Mechanism RFC 3264 An Offer/Answer Model with SDP Change Media Characteristicsby Re-INVITE (or UPDATE) Hold/Resume Media Stream Advanced Scenarios Examples Draft Under definition Will use Grouping of Media Lines in the SIP RFC 3388 Will use 'SDP Simple Capability Declaration' draft-andreasen-mmusic- sdp-simcap-05.txt
Video support in SIP
Freeze Picture Command (Encoder -> Decoder) Fast Update Command (Decoder -> Encoder) * CODEC = enCOder DECoder Two Basic Video Controls
XML Schema in INFO The IETF draft draft-levin-mmusic-xml-media- control-01.txt draft-levin-mmusic-xml-media- control-01.txt Implemented already by ViaIP MCU (RADVISION) RTC Messenger (Microsoft) eConf (France Telecom) Tech Currently defines Fast Update and Freeze Picture Transported over SIP INFO
SIP for Conferencing
SIPPING Conferencing Design team in IETF SIPPING Requirements Document SIPPING Framework Document SIPPING Conference Event Package (NOTIFYs of participant list) SIPPING Call Control – Conferencing Usage Document Documents listed at http://softarmor.com/sipping/teams/conf/ http://softarmor.com/sipping/teams/conf/
SIP Tightly Coupled Conference Association of User Agents with a single central point – i.e. Focus. Focus is a UA that Maintains a SIP dialog with each conference participant and internally correlates among them. Can be implemented either by a participant or by a dedicated server. In centralized model, focus does media mixing In decentralized model, focus controls endpoint mixing
SIP Conference Identification A SIP Conference is uniquely identified by a globally routable Conference URI. Focus includes the Conference URI (followed by the feature tag isfocus) in the Contact of each message belonging to a conference dialog. As a result, any RFC 3261 compliant UA can participate in a conference.
A Conference and its URI Exist Dial In Users INVITE carries the Conference URI in the Request-URI. Servers 200 OK carries the Conference URI in the Contact. Dial Out Servers INVITE carries the Conference URI in the Contact. Conference-aware user understands the meaning of isfocus feature tag. Additional Participants Can be added by sending a REFER with the Refer-To of the Conference URI.
Ad-Hoc Conference Creation using Conference Factory URI Definition: an INVITE sent to this SIP URI will create an ad-hoc conference. Conference Factory URI can be programmed on a Conference button on a SIP phone, or published on a webpage. The new Conference URI is returned to the creator in the Contact in the 200 OK.
Participants List SIP Event Packages for Call and Conference draft-rosenberg-sip-call-package-00.txt The Body of NOTIFY Contains a Conference Information XML Document of MIME Type application/conference-info+xml List of Users User Identity Status active|departed|booted|failed Etc.
Non-SIP Further Potential Conferencing work in IETF Conference Policy Control Protocol (CPCP) Used to create conferences by automata Used by conference owner to change policies Media Policy Control Protocol (MPCP) Users control how media is mixed/presented Floor Control Protocol
RADVISION SIP Conferencing Solution
Multimedia Centralized Conferencing MCU is a SIP User Agent The Conferencing Functions are Implemented by the MCU whenever possible Mixing of Media Streams Conferencing and Floor Control The Easiest Task from End User Perspective Looks Like a Point-to-Point Call with the MCU Does not Necessarily Require Special Conferencing Support
Addressing the Scalability Issue To Make the Solution More Scalable, the MCUs can be further cascaded It is Transparent to the End Users
ISDN/CSN Multimedia Centralized Conferencing Mobile Phone PSTN Phone MS MessengerSIP VideophoneH.323 Application H.320 System Internet Video and Voice MCU SIP Phone
MCU Key Features Voice Activated or Continuous Presence modes Video Algorithms - H.261,H.263, H.263++ Audio Algorithms – G.711, G.722, G.728, G.723.1, G.729 A/B, Siren/G722.1 Web based Administration and Conference Control XML Based 3 rd Party Call Control API Video Transcoding Resolution: CIF, QCIF, 4CIF T.120 Data Collaboration Some features require optional hardware/software
Clustered MCUs – Up to 600 channels distributed on 6 cards that can be physically located in different chassis and different locations Best Performance and Least Latency (300 msec vs. 1 sec) Greater port density – Up to 280 concurrent calls at 384kbps in a single chassis (Voice activated) Sub-Conferencing Downspeeding Duo-video support (Tandberg endpoints) MCU Key Features continued… Some features require optional hardware/software
Lecture Mode (multiple streams) Active Speaker Operator Assistance Second Ethernet port activated for management MCU Key Features continued… Some features require optional hardware/software
Advanced Video Processing Continuous Presence INVISION and viaIP100 -13 participants on one screen viaIP400 – 16 participants on one screen Many layout options Multi-layouts for same conference Intelligent Symmetric/Asymmetric CP Rate/Speed Matching Including more than two speeds Symmetric video streams Required by ISDN endpoints Efficient WAN bandwidth utilization
Advanced Video Processing continued… Exit/Entry audio indications On-the-Fly video mode/layout change Any layout to any layout Secured web access (HTTPS) Conference Control DTMF H.243 Text Overlay Drag and drop Some features require optional hardware/software
WEB Conferencing and Floor Control RADVISIONs XML-based Open API: Create/Terminate Conference Take/Release Conference Control Invite/Disconnect Participant Get Conference List and details Get Number Of Participants In Conference Get Participant Details Get Conference Video Configuration Lock/Unlock Participant Video Mute/Enable Audio Channel Conferencing Control API
IM1st Ad-hoc Conferencing Integration with the Microsoft RTC Conference initiation by adding a Conference Assistant Buddy to the IM chat Existing conference control Video window is logically attached to multiparty IM