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112/04/19 1
Virtual Media Center: A Generic Architecture for Virtual Media Center: A Generic Architecture for Distributed Video-On-Demand ServicesDistributed Video-On-Demand Services
Date: 30 April 2004
Presented by: Lee KaYan,Sunny
Supervisor: Prof. Michael R. Lyu
Department of Computer Science & Engineering
The Chinese University of Hong Kong
Master of Science in Computer Science
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OutlineOutline
Motivation Related Work Virtual Media Center (VMC) Services Characteristics Technologies Used: Web Service and
CORBA System Architecture Implementation Details Future Works and Enhancements
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MotivationMotivation
VOD is a bandwidth demand, the capacity of concurrent users is limited at present network equipment and technologies. A simple and efficiency server selection mechanism is needed
Multimedia technologies such as compression, security and streaming protocol may change in the future. A framework to provide multimedia streaming service with the capability to adapting technologies change is needed
To implement a application called “Virtual Media Center” under this framework
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Related WorkRelated Work Video-on-Demand (VOD)
– VOD is a service that allow users to view any video at any time and can use VCR-like functions
– Currently, the most popular and cheap technology for VOD is streaming over Internet
Distributed Systems– Common VOD architectures are distributed systems (DVOD)– Distribution can be distributed system components,
distributed streaming servers, distributed media content and distributed transmission source (stripping)
Major solutions on DVOD– Replicate strategy for video content– Metrics based streaming server selection– Set-Top box for buffering, caching and decryption
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Virtual Media Center (VMC) ServicesVirtual Media Center (VMC) Services
Video Streaming for VODReal-time TV Real-time Web CamAd hoc streamingAuto server selectionCORBA API Web service API
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CharacteristicsCharacteristics
Distributed server architectureCORBA and Web service interface
between serverIntegration of heterogeneous
streaming technology and systemBy pass firewallWeb user interface
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Technologies used: Web Service and CORBATechnologies used: Web Service and CORBA
Why CORBA–Middleware for heterogeneous network,
computer hardware, operating system and programming language
– Best for interface between heterogeneous streaming server among different technology or content provider
– Drawback: difficult to pass firewall in distributed environment
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Technologies Used: CORBA and Web ServiceTechnologies Used: CORBA and Web Service
Why Web service– Can pass firewall – Best for interface between VMC and
different content providers– API for Web application– Best for remote administration,
monitoring etc.– Provide catalogue to remote Web server
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System ArchitectureSystem Architecture
Roles in VMC: System operator Content Provider Subscriber
Content Provider Content Provider
VMC Operator
Subscriber
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System ArchitectureSystem Architecture
Components in VMC: Web server – provide
catalogue of media content to subscriber
Database server – provide information storage
Streaming server – provide multimedia content storage and streaming to subscriber
Web server
Streaming server
Database server
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System ArchitectureSystem Architecture
Scenario for VOD: One central Web
server for Internet access
Many streaming server distributed in different geographic location for load balancing
Subscribers are scattered in the Internet
Web server
Streaming server
Streaming server Streaming serverSubscriber
SubscriberSubscriber
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System ArchitectureSystem Architecture
Scenario for Real-time broadcast:
Use Audio/Video capture device such as Web Cam or TV turner card
Web Cam or TV turner card can directly connected to streaming server
Web server
Streaming server
Streaming server
Subscriber
TV Antenna connected to
TV turner card
Web Cam
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System ArchitectureSystem Architecture
Scenario for Mobile user: Remote Web server for
Mobile device Consume catalogue
from VMC through Web service API
Choice best streaming server to delivery content by Remote Web server
Streaming server
VMC Web Service
Remote Web Server Wireless Access point
3G Device
Smartphone
Notebook
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System ArchitectureSystem Architecture
Scenario for ad hoc multimedia streaming:
Ad hoc streaming source registration through Web service API
Mobile user can real-time broadcast through wireless network
Suitable for news broadcast, remote monitoring etc.
Notebook
Web Cam
Streaming server
VMC Web Server
Web Service API
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System ArchitectureSystem Architecture
Scenario for local and remote servers:
CORBA within firewall Web service outside
firewall For distributed
streaming servers For independent
content providers to contribute their own streaming servers
Router
Firewall
Streaming server
VMC Web Server
Web Service
CORBA
Firewall
Router
Streaming server
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System ArchitectureSystem Architecture
Scenario for real-time server selection:
Round-Trip Time (RTT)
Server CPU utilization Server allocated
bandwidth Server connected
clients
VMC
Streaming serverStreaming server
CPU Utilization, Allocated Bandwidth and Connected Clients
Subscriber
Round-Trip Time (RTT) information
RTT Function Call RTT Function Call
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System ArchitectureSystem Architecture
Scenario for RTT Collection: Optimal
– Between subscriber and streaming server
– Need subscriber accept mobile code or install RTT client
Less optimal– Between remote Web server and
streaming server– Remote Web server should
located near subscriber– Remote Web server responsible
collect RTT and update to VMC periodically
– No mobile code or install RTT client to subscriber
– Best solution for mobile subscriber
VMC
Remote Web Server
Streaming server
Streaming server
Mobile Subscriber
RTT
RTTRTT
RTT
Mobile code or RTT Client Installed
Collect RTT periodically
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System ArchitectureSystem Architecture
A Generic Implementation Architecture
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System ArchitectureSystem Architecture
Logical Components
Client Application
Streaming Server RTT
Clie
nt
Virtual Media Center
Web ServiceStreaming Service Web Server
Server Status MonitorCORB
A-O
RB
CORB
A-O
RB
CORB
AN
amin
g Se
rvic
e
Web
Ser
vice
Cl
ient
RTT
Serv
er
Resources Monitor(CPU Loading, Allocated
bandwidth and Connected Client)
HTTP
SOAP
SOA
P
Remote Web Server
Catalogue Viewer
HTT
P, H
TTPS
Media Streaming Player
Web
Ser
vice
Media Catalogue
HTT
P, R
TSP,
MM
S
Media Content
Reso
urce
s Met
rics
Database Server
Media Archive
TV Turner Card
Auidi/Video Capture HW RTT Metric
Distributed Location * Multiple Instances
*
*
*
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ImplementationImplementation
Client Application: Microsoft Windows
Streaming Server: Windows Server 2003
.NET
Re
mot
ing
Virtual Media Center: Windows XP Professional, IIS 6, ASP.NET
Web ServiceStreaming Service: Windows Media Service 9
and Windows Media EncoderWeb Server
Server Status Monitor:C#.NETCO
RBA
-ORB
: om
niO
RB
CORB
A-O
RB:
omni
ORB
CORB
A N
amin
g Se
rvic
e: o
mni
Nam
es
C#.N
ET.N
ET
Rem
otin
g
Resources Monitor(CPU Loading, Allocated
bandwidth and Connected Client):Web Services - C#.NET
OrCORBA-VC++7.0
HTTP
SOAP
SOA
P
ASP.NET Mobile
IE 6 or Above
HTT
P, H
TTPS
Windows Media Player 9 Series
Web
Ser
vice
Media Catalogue
HTT
P, R
TSP,
MM
S
Media Content
Reso
urce
s Met
rics
Database Server:
MS SQL Server
Media Archive: *.WMV
TV Turner Card: TVB
Auidi/Video Capture
HW: Web Cam
RTT Metric
Distributed Location * Multiple Instances
*
*
*
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Implementation DetailsImplementation Details
Database structure in SQL server 2000:
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Implementation DetailsImplementation Details
In VMC server: Web Server
– Windows 2003 Server– Internet Information Server 6– ASP.NET 1.1
Web Service– Visual Studio .NET 2003 C#
VMC Monitor (e.g. Collect RTT, server status etc.)– Visual Studio .NET 2003 C#– .NET Remoting
Database server– SQL server 2000 MSDE version
CORBA Naming Service– omniORB Naming Service
CORBA server object (for streaming server CPU utilization, allocated bandwidth and connected clients update)– omniORB ORB + VS.NET 2002 VC++ 7.0
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Implementation DetailsImplementation Details
In Streaming server: VOD service
– Microsoft Windows Media Server 9– HTTP, MMS and RTSP– Windows Media File format (*.wmv)
Real-time broadcast for TV and Web Cam– Windows Media Encoder
RTT Server– Visual Studio .NET 2003 C#– .NET remoting– Windows service
CPU utilization, allocated bandwidth and connected clients update– CORBA client: omniORB ORB + VS.NET 2002 VC++ 7.0– Web service client: VS.NET 2003 C#
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Implementation DetailsImplementation Details
Remote Web Server: (for Wireless Mobile Device, Pocket PC version) Web Server
– Windows 2003 Server– Internet Information Server 6– ASP.NET 1.1
Pocket PC requirement– Microsoft Pocket PC 2003– Windows Media Player 9
Development and testing– Visual Studio .NET 2003 C#– ASP.NET 1.1 Mobile Control– .NET compact framework 1.1– Pocket PC 2003 Emulator– Pocket PC 2003 Phone Edition Emulator
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Implementation DetailsImplementation Details
Programs in VMC server: omniNames VMC_impl VMCMonitor
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Implementation DetailsImplementation Details
Programs in streaming server: WMSMonitor VSSMonitor Windows Service
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Implementation DetailsImplementation Details
System Monitoring Tool: S (s.exe)
Syntax:
s <serverid> [<serverip>]
e.g. s 0
(0 means display the run-time information for all servers)
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Implementation DetailsImplementation Details
Subscriber Interface:
VMC Home Page
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Implementation DetailsImplementation Details
Subscriber Interface:
Catalogue Page
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Implementation DetailsImplementation Details
Subscriber Interface:
Catalogue Page -
Filter Functions
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Implementation DetailsImplementation Details
Subscriber Interface:
Select Server Page
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Implementation DetailsImplementation Details
Subscriber Interface:
VOD Session Page
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Advantage and DisadvantageAdvantage and Disadvantage Advantage
– CORBA and Web Service are well defined standard– Independent to individual streaming technologies– Web Interface for multiple devices: PC, mobile notebook,
Pocket, Palm, 3G phone or Smart phone etc.– Real-time server selection– RTT independent to any underlying network path selection
algorithm and easy to implement Disadvantage
– Subscriber must installed a build in streaming player in Web browser to decode the target streaming
– Remote Web server must located nearest to subscriber to obtain the best RTT estimation for subscriber
– Streaming quality and concurrent connections are still limited to underlying bandwidth, compression technology and network equipment
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Future Works and EnhancementsFuture Works and Enhancements
Implementation– Interoperability between different ORB– Mobile code for RTT client– Native player install in subscriber device– Test remote Web server for mobile device on real device– Publish Web service on UDDI directory
Testing– Stress test on efficiency of RTT, CPU utilization,
allocated bandwidth and connected clients– Improvement of concurrent clients capacity on real-time
server selection
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End of Presentation
Thanks !