Streaming Media Supplement sa2150 and sa2250

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This chapter assumes that you understand the elements of a proxy caching deployment, which are explained in
Chapter 2‚ Media-IXT Deployment Scenarios.
In this chapter, we explain feature implementation for Windows Media Technologies (WMT) media
streaming.
We discuss each pertinent element of a deployment in turn, following the same order as the previous chapters:
• “Understanding forward proxy, reverse proxy, and transparency for WMT” below
• “Understanding multi-bitrate clips and WMT” on page 45
• “Understanding hierarchy and WMT” on page 45
• “Understanding live passthrough, live splitting, and hierarchical live splitting for WMT” on page 45
• “Understanding clustering and WMT” on page 47
• “Understanding VIP failover and WMT” on page 47
• “Understanding CDS preload and WMT” on page 47
• “Understanding selective caching and WMT” on page 48
• “Understanding authentication and WMT” on page 48
• “Understanding firewalls and WMT” on page 48
Understanding forward proxy, reverse proxy, and
transparency for WMT
This section discusses:
• WMT streaming essentials
• how WMT streaming works with no proxy cache present
• how a proxy cache fits into the scenario
• an example of how Media-IXT rewrites WMT metafiles
We describe WMT streaming based on the use of an origin WMT server for streaming content along with an
HTTP server for WMT metafiles. This is not the only way to do WMT streaming. The features of Media-IXT
that work with HTTP servers and WMT metafiles can be configured on or off, and Media-IXT performs WMT
streaming in deployments with or without them. MMS transparency provides an alternative basis for deploying
Media-IXT to stream WMT content.
This manual cannot describe all the possible ways to do WMT streaming. For a brief introduction to this
subject, see “WMT streaming deployments based on MMS transparency” on page 43.
WMT streaming essentials
To understand WMT streaming, you need to know about WMT metafiles and media content URLs.
WMT metafiles are written in a scripting language, called ASX, that controls Windows Media Player. WMT
metafiles have one of three suffixes: .asx, .wax or .wvx.
The URL of the actual WMT streaming media content, called the media content URL, is different from the URL
of the WMT metafile. The media content URL:
• includes the name of a file in a Windows Media media streaming format, called ASF; these files have one
of three suffixes: .asf, .wmv or .wma.
4 Understanding Media-IXT and WMT