1 streaming servers presented by: joy chakraborty martin stavrev
TRANSCRIPT
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OVERVIEW
What is ‘Streaming’Why Use Streaming?Streaming TechnologiesStreaming ProductsWindows Media Technologies
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WHAT IS STREAMING ?
Method of making audio, video and other multimedia available in real-time over the Internet or corporate intranets
Streaming ensures no download waitNo files to take up space on your hard
disk.
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STREAMING MEDIA
Streaming technology is not new It has been around since the inception of
the radio (1897). We just called it broadcast.
Streaming media is content that contains audio, video and other media types.
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WHY USE STREAMING ?
Streaming video can be used for live or recorded events
Provides truly interactive, on-demand audio and video
No need for time taking downloadsCorporate communications and training
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CURRENT ISSUESThe Internet was not designed for real
time streaming.Limited bandwidth, latency, noise, &
packet loss Retransmission and out of order packet
delivery
Continued….
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CURRENT ISSUESLive or on-demand streaming is a time
critical applicationSensitive to the variation in delay
inherent in a shared access network like the Internet
Majority of end users access the Internet over very narrowband dial up links
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THE ‘streaming’ SOLUTIONStreaming uses ‘Buffering’Buffering irons out the natural traffic
variations inherent on the Internet. Streamed broadcast starts to play at the
same time as more content is being downloaded
Media file can be of any length and can run over Internet bandwidths
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THE STREAMING MODELThe components of an end to end
streaming system are:
Client (Media Player) Streaming Server Streaming Media Production Tools
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STREAMING TECHNOLOGIES
Unicast A separate copy of the data is sent from the
source to each client that requests it. Broadcast
A single copy of the data is sent to all clients on the network
Multicast sends a single copy of the data to those
clients who request it.
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UNICASTThe bulk of the traffic on today's
networks is unicastA separate copy of the data is sent
from the source to each client that requests it
Unicast wastes bandwidth by sending multiple copies of the data
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BROADCAST A single copy of the data is sent to all
clients on the network Broadcast wastes bandwidth by sending
the data to the whole network whether or not the data is wanted
Broadcast slows client machine - each client must process the broadcast data whether or not the broadcast is of interest
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MULTICASTMulticasting sends a single copy of
the data to those clients who request it
Multicasting takes the strengths of unicast and broadcast and avoids their weaknesses
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MULTICASTNo matter how many connections,
there's still only one connection at the server.
With multicasting, the client must notify the server that it wishes to receive the multicast stream, eliminating the capability of on-demand content
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MULTICAST Comparison of network load per client when
unicasting an 8-Kbps PCM audio stream and multicasting the stream
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THE MBONE Internet Multicast Backbone Most widely known and used multicast
enabled network A virtual network consisting of those
portions of the Internet, sometimes called multicast islands, on which multicasting has been enabled
Continued….
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THE MBONE MBone has been in place since 1992 and
has grown to more than 2000 subnets. Has been used to multicast live audio and
video showing Internet Engineering Task Force conferences, NASA astronauts working in space, and the Rolling Stones in concert.
MBone has successfully demonstrated the practicality and utility of using multicasting to send multimedia across the network.
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MULTICAST ISLANDS AND TUNNELS
Multicasts that must travel across areas of the Internet that are not yet multicast-enabled are sent as unicasts until they reach the next multicast enabled island.
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HOW MULTICASTING WORKS
Multicasting follows a push model of communications
The user is simply instructing the computer's network card to listen to a particular IP address for the multicast.
Multicast addresses are Class D IP addresses ranging from 224.0.0.0 to 239.255.255.255
The computer originating the multicast does not need to know who has decided to receive it.
Continued…
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MULTICASTING REQUIREMENTS
Clients must have a way to learn when a multicast of interest is available.
Clients must have a way to signal that they want to receive the multicast.
The network must have a way to efficiently route data to those clients who want to receive it.
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ANNOUNCING MULTICASTS
Multicasts are announced in advance so that clients know when a multicast is available
On the MBone, multicasts are typically announced using the Session Description Protocol (SDP)
The announcement information is multicast to a well-known IP address and port where clients running the session directory tool receive this information
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JOINING MULTICAST GROUPS
To signal that they want to receive a multicast, clients join the group to which the multicast is directed.
The Internet Group Management Protocol (IGMP) handles this task
Groups are dynamic: clients can join or leave at any time
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MULTICAST GROUPS When a client joins a group, it initiates
two processes First, an IGMP message is sent to the client's
local router to inform the router that the client wants to receive data sent to the group
Second, the client sets its IP process and network card to receive the multicast on the group's address and port
When a group has no members, it ceases to exist on the network, releasing network bandwidth.
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QUICKTIMEMature technology (Developed 1991)Mac OS, but Darwin Streaming Server
available for other platforms.Open Plug-in Feature (3rd party codecs)MPEG 1 and 4Quicktime 5 (beta) – support for
immersive virtual reality
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REAL MEDIA70% Market Share (Installed on 90%)SureStream Technology - adjusts the
streamed data rate to suit the client's connectivity (Intel partner)
Supports SMILRealServer (25 users free)
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WINDOWS MEDIA SERVICESFree with Windows 2000 Server Relatively newProprietary ASF codec, MPEG4, SMIL Intelligent Streaming Microsoft Media Server (MMS), HTTP
protocol
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WINDOWS MEDIA TECHNOLOGIES
Internet broadband-ready platform for the creation, distribution, and playback of digital media files.
Newest version of the industry's leading digital media platform
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COMPONENTSWindows Media PlayerWindows Media ServicesWindows Media EncoderWindows Media FormatWindows Media SDKWindows Media Rights Manager
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WINDOWS MEDIA SERVICES
Used to host media files to be streamed over the internet/intranet
A digital media platform that offers employees, partners, and customers exceptional scalability, reliability, and quality
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WINDOWS MEDIA SERVICES FEATURES
Most Scalable Uses Windows NT Server multithreading and
processor support to allow for maximum scalability. Pentium II system can support over 2000 28.8 Kbps connections
Provides freely available tools for independent organizations to document concurrent streams delivered on one machine
Continued….
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WINDOWS MEDIA SERVICES FEATURES
Most Reliable Tight integration between Windows Media
Services and Windows 2000 creates the most reliable streaming platform
ZD Labs reported that Windows Media Services delivered 26 billion packets of data with 99.9999999% accuracy over more than 12 days of continuous streaming of over 2,400 broadband streams.
Continued….
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WINDOWS MEDIA SERVICES FEATURES
Highest Quality Output Windows Media Services supports the industry-
leading Windows Media format Only video codec that offers near-DVD quality
video at as low as 750 Kbps The Windows Media audio format, which offers
CD-quality audio at 96 Kbps The revolutionary Windows Media Screen codec,
which offers exceptional reproductions of computer screen movement at resolutions as high as 800 × 600 and data rates as low as 22 Kbps. Continued….
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WINDOWS MEDIA SERVICES FEATURES
Highest Return On Investment Windows Media Services are built directly
into Windows 2000 Server, offering complete integration with corporate infrastructure
No additional per-stream or per-seat licensing is required for Windows Media, thus minimizing deployment costs
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STREAMING CONTENT SETUP
Basic steps for creating and hosting streaming content using Windows Media Technologies:
1. Encoding Windows Media Files
2. Hosting Encoded Content
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WINDOWS MEDIA FILES Format created by Microsoft for authoring,
storing, editing, distributing, streaming, and playing multimedia content
Designed specifically to stream the content over networks, like the Internet
Highly flexible format that can be used for streaming audio, video, slide shows, and synchronized events
Windows Media Format enables content to be delivered to end users as a continuous flow of data
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ENCODING WINDOWS MEDIA FILES
Windows Media file may be created from a .wav, .avi, or .mp3 file
Windows Media file can also contain JPEG or .bmp image
Source Files may be PowerPoint Presentation slides
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ENCODING TOOLSMedia On-Demand Producer (Microsoft)Windows Media EncoderWindows Media AuthorFree with Windows 2000 ServerSMIL creationConvert .wav, .avi, or .mp3 to Windows
Media file format (.asf, .wma, .wmv)
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WEB SERVER HOSTING Creating and hosting Windows Media
metafiles - a metafile is needed for each Windows Media file.
A Windows Media metafile is a small text file that contains the URL of a Windows Media file.
Adding links to the metafiles from a Web page - each link points to the metafile for a Windows Media file instead of directly to the file.
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Windows Metafile Example:
<ASX version="3">
<Entry>
<ref HREF="Path/File.asf" />
</Entry>
</ASX>
WEB SERVER HOSTING
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WEB SERVER HOSTING PROBLEMS
Web Server not designed for streaming media files.
Playback can be interrupted by periods of buffering.
Cannot stream files that have been encoded with multiple bit rates.
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WINDOWS MEDIA SERVER HOSTING
If you require higher quality and better server resource utilization, it makes sense to host your content on a dedicated Windows Media server.
Copy the Windows Media files to the ASFroot directory, and copy the metafiles to the Web server
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WINDOWS MEDIA SERVER HOSTING
Windows Media Services can stream two types of content: Broadcast and On-demand.
Delivered to clients with a unicast connection
Broadcast content can also be delivered with a multicast connection
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CONTENT VIEWING Windows Media Player can play back audio
and video content the same whether a file is on a Windows Media server, a Web server, a network server, or a local hard disk
A Windows Media server is designed to handle busy, congested networks and low-bandwidth connections to client computers running Windows Media Player.
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ADVANTAGES Stream through most firewalls Indexing - provides end users with a means of
fast-forwarding and rewinding through a file that is being streamed
Stream content with Digital Rights Management - Windows Media Rights Manager - distribute licensed digital media over the Internet with superior audio quality.
Windows Media security - Security features can be used to limit access to media on a Windows Media server
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ADVANTAGES Live Streaming - Playback of a broadcast stream
is controlled at the point where the stream originates and includes live streaming
Intelligent streaming - interaction between a Windows Media server and Windows Media Player to optimize the stream for the current available bandwidth
Administering and logging - control how a Windows Media server manages live content and files and monitor overall system activity in real time, log files
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ADVANTAGES Best-of-breed Multicast and Server
Administration - easy-to-use server administration with extensive wizards that guide the user through procedures, such as setting up a multicast, monitoring a server, or switching between multiple live sources.
Support for Advanced Applications and Pay-Per-View (PPV) - Includes pre-built and documented interfaces to Site Server Ad Server, Site Server Commerce Server, and Site Server Membership server. This functionality is the core of pay-per-view and dynamic ad-insertion applications of streaming media on the Internet.
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THE FUTUREHigh bandwidth connections will make
streaming more popular.Guaranteed Quality of Service over IP
will improve streaming quality.The streaming model will be used more
widely to provide multimedia content.
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CONCLUSIONStreaming media is the future of online
entertainment.Low cost way to deliver interactive
multimedia.Windows Media Services: a
comprehensive suite for streaming.
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RESOURCEShttp://msdn.microsoft.com/library/default
.asp?url=/library/en-us/dnwmt/html/contcreation.asp?frame=true
http://www.publicsource.apple.com/projects/streaming/
http://www.cultivate-int.org/issue4/video/
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RESOURCEShttp://www.microsoft.com/windows/
windowsmedia/en/overview/default.asphttp://msdn.microsoft.com/library/
default.asp?url=/library/en-us/dnwmt/html/webserver.asp
http://www.zdnet.com/sp/stories/issue/0,4537,2471928-4,00.html
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RESOURCEShttp://www.nwfusion.com/research/
streaming.htmlhttp://www.microsoft.com/windows/
windowsmedia/en/support/faq_strm.asphttp://www.broadcastengineering.com/
html/2000/august/features/streamMedia_0800.htm
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RESOURCEShttp://www.savetz.com/mbone/http://www.cis.ohio-state.edu/~jain/
cis788-97/ip_multicast/ http://www.real.comhttp://www.opensource.apple.com/
projects/streaming