Streaming Media Supplement sa2150 and sa2250

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Chapter 9 Configuring Media-IXT for QuickTime
Configuring an origin QuickTime server for use with
Media-IXT
The Apple
®
Darwin Streaming Server, version 2.x, is currently the prevalent origin QuickTime server.
The following procedure makes it possible for Media-IXT to cache the maximum percentage of QuickTime
content served by Darwin 2.x. See “QuickTime Logging” on page 107.
To configure an origin QuickTime server for use with Media-IXT:
1. Open the configuration file, streamingserver.conf, in an editor.
2. Change the value of the rtsp_timeout parameter to 0 (zero).
The relevant line should read:
rtsp_timeout 0
Configuring Media-IXT for streaming over HTTP
Streaming over HTTP is normally only a last-resort streaming strategy, chosen by a browser as a fallback after
its preferred strategies fail. Rarely, streaming over HTTP is chosen by a network designer as the primary
streaming strategy for a deployment.
Streaming servers mark streams served through HTTP as non-cacheable, so Media-IXT, being a cache, can not
provide any bandwidth savings or service improvements for such service.
Streaming over HTTP works by making one persistent connection from the origin server to Media-IXT, and
another from Media-IXT to the client. Media-IXT terminates HTTP connections after a configurable period of
time whose default value is too brief for streaming over HTTP to work properly.
If your deployment relies on streaming over HTTP, you must tune Media-IXT’s HTTP timeout values so that
Media-IXT does not terminate streaming HTTP transactions before the play is complete.
Here are the relevant variables as they appear in the records.config file:
CONFIG proxy.config.http.transaction_no_activity_timeout_in INT 120
CONFIG proxy.config.http.transaction_no_activity_timeout_out INT 120
CONFIG proxy.config.http.transaction_active_timeout_in INT 7200
CONFIG proxy.config.http.transaction_active_timeout_out INT 7200
Note their default values, which are in seconds: 120 seconds equals two minutes; 7200 seconds equals two
hours.
These variables are documented in the HP Cache Server Appliance Administrator Guide, although streaming
over HTTP is not.
To configure Media-IXT for streaming over HTTP:
1. Decide which clip you plan to stream over HTTP has the longest duration. Add some extra time to that
duration and convert the total to seconds. We will call this value X.
2. Edit records.config such that all four timeout variables have the value X instead of the default values.
So, if X is 14520 for example (where your longest clip is four hours, or 14400 seconds, plus a margin of two
minutes), you have:
CONFIG proxy.config.http.transaction_no_activity_timeout_in INT 14520
CONFIG proxy.config.http.transaction_no_activity_timeout_out INT 14520
NOTE This procedure affects all streaming formats: RealNetworks, WMT and QuickTime.