Transcript Streaming Servers

STREAMING
SERVERS
Presented By:
Joy Chakraborty
Martin Stavrev
Modified By: N. Ganesan
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OVERVIEW
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What is ‘Streaming’
Why Use Streaming?
Streaming Technologies
Streaming Products
Windows 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 wait
• No 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 downloads
• Corporate communications and training
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CURRENT ISSUES
• The 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 ISSUES
• Live or on-demand streaming is a time
critical application
• Sensitive 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’ SOLUTION
• Streaming 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 MODEL
• The 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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UNICAST
• The bulk of the traffic on today's
networks is unicast
• A 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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MULTICAST
• Multicasting 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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MULTICAST
• No 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
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the network.
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.
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HOW MULTICASTING
WORKS
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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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MULTICAST ROUTING
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STREAMING PRODUCTS
• Quicktime (Apple)
• RealMedia (Real Networks)
• Windows Media Services (Microsoft)
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QUICKTIME
• Mature technology (Developed 1991)
• Mac OS, but Darwin Streaming Server
available for other platforms.
• Open Plug-in Feature (3rd party codecs)
• MPEG 1 and 4
• Quicktime 5 (beta) – support for
immersive virtual reality
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REAL MEDIA
• 70% Market Share (Installed on 90%)
• SureStream Technology - adjusts the
streamed data rate to suit the client's
connectivity (Intel partner)
• Supports SMIL
• RealServer (25 users free)
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WINDOWS MEDIA SERVICES
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Free with Windows 2000 Server
Relatively new
Proprietary 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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COMPONENTS
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Windows Media Player
Windows Media Services
Windows Media Encoder
Windows Media Format
Windows Media SDK
Windows 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
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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 TOOLS
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Media On-Demand Producer (Microsoft)
Windows Media Encoder
Windows Media Author
Free with Windows 2000 Server
SMIL creation
Convert .wav, .avi, or .mp3 to Windows
Media file format (.asf, .wma, .wmv)
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CONTENT HOSTING
• Two Choices of hosting:
– On a Web Server
– On to Windows Media Server
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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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WEB SERVER HOSTING
• Windows Metafile Example:
<ASX version="3">
<Entry>
<ref HREF="Path/File.asf" />
</Entry>
</ASX>
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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 lowbandwidth connections to client computers
running Windows Media Player.
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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 PayPer-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 FUTURE
• High 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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CONCLUSION
• Streaming 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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RESOURCES
• http://msdn.microsoft.com/library/default
.asp?url=/library/enus/dnwmt/html/contcreation.asp?frame=
true
• http://www.publicsource.apple.com/proj
ects/streaming/
• http://www.cultivate-int.org/issue4/video/
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RESOURCES
• http://www.microsoft.com/windows/wind
owsmedia/en/overview/default.asp
• http://msdn.microsoft.com/library/default
.asp?url=/library/enus/dnwmt/html/webserver.asp
• http://www.zdnet.com/sp/stories/issue/0,
4537,2471928-4,00.html
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RESOURCES
• http://www.nwfusion.com/research/strea
ming.html
• http://www.microsoft.com/windows/wind
owsmedia/en/support/faq_strm.asp
• http://www.broadcastengineering.com/ht
ml/2000/august/features/streamMedia_
0800.htm
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RESOURCES
• http://www.savetz.com/mbone/
• http://www.cis.ohiostate.edu/~jain/cis788-97/ip_multicast/
• http://www.real.com
• http://www.opensource.apple.com/proje
cts/streaming
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The End
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