Streaming Media Supplement sa2150 and sa2250

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Chapter 5 Understanding Media-IXT and QuickTime
Understanding reverse proxy caching for QuickTime
In reverse proxy caching the advertised origin server name and the host name of the origin QuickTime server
are different. The Media-IXT needs to know the origin QuickTime server name that corresponds to the
advertised server name.
For example, the advertised media server name might be greatmovies.com, and the origin QuickTime
server might be reallygreatmovies.com.
You must configure Media-IXT to understand the correspondence between advertised server names the origin
QuickTime server hostnames by editing the remap.config configuration file. In doing so, you put
remapping rules in remap.config
See Chapter 9‚ Configuring Media-IXT for QuickTime.
QuickTime reverse proxy caching follows these steps:
1. The QuickTime Player sends an RTSP request, which contains a URL of the form
rtsp://<server:port>/<optional file name info>/
The server part of the URL contains the advertised site name, which Media-IXT answers on the port given
in the port part of the URL. So a QuickTime Player might send a request containing the URL:
rtsp://greatmovies.com:554/epic.mov/
2. Media-IXT finds the hostname of the origin QuickTime server in the map rules contained in the
remap.config configuration file.
Figure 5-3. QuickTime transparent proxy caching example (concluded)
NOTE Remapping rules for RealNetworks and QuickTime content use the Media-IXT
hostname and not its IP address, which is different from WMT remapping rules, which
use the Media-IXT IP address, not hostname.
L4 Sw it ch
Client browser with
QuickTime player
6
udp
4
tcp
5
Media-IXT opensa TCP connection to the origin QuickTime server.
Media-IXT determines whether the requested content is in cache, and whether it isfresh.
The content is in cache and is fresh, soMedia-IXT doesnot need to pull the content from
the origin server.
Media-IXT streams cont ent to QuickTime player.
4
5
6
Origin
QuickTime
server
Me ia-IXTd