Streaming Media Supplement sa2150 and sa2250

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Chapter 8 Configuring Media-IXT for WMT
The MMS protocol uses UDP for retransmission requests. WCCP2 routers do not have the capability to handle
UDP retransmission requests. For more information about these issues, and sample WCCP2 router
configurations providing transparency for streaming media protocols (RTSP and MMS) as well as HTTP, go to
the HP Technical Support website:
h
ttp://www.hp.com/serverappliances/support/
Configuring reverse proxy caching for WMT
For HTTP and MMS, the mapping rules for reverse proxy caching are in the remap.config file. Be aware
that these directions document only one scenario for reverse proxy, in which Media-IXT answers to the
advertised name of the website. That is, the advertised name of the website resolves to an IP address which is
Media-IXT’s, whether virtual or not.
Reverse proxy mapping rules must be different when a different reverse proxy scenario applies. See the
explanation of these issues in “Understanding forward proxy, reverse proxy, and transparency” on page 6.
Also be aware that writing correct mapping rules is necessary but not sufficient for reverse proxy to work
correctly. The Fully Qualified Domain Name portion of the URLs of the origin server’s content must contain
the advertised name of the website. Again, see the section just cited.
Remember that WMT streaming requires both an origin Windows Media server for the streaming content, and
an HTTP server for the WMT metafiles. You must decide whether your Media-IXT is providing reverse proxy
caching for one or both. Each requires a separate set of rules.
For this configuration example we assume:
• a Media-IXT host, whose IP address is 10.10.10.10
,
and which answers to www.pix.com
• an HTTP server which contains the .html pages that make up the website, which answers to
relay.pix.com.
• a Windows Media server where our actual Windows Media streaming content resides in the form of .asf
files; its IP address is 11.11.11.11, and it answers to source.pix.com
The .html
pages on the HTTP server contain links to several .asx files, each of which corresponds to a
.asf file that resides on the Windows Media server.
If we followed accepted practice in setting up the site originally, each .html file which resides on the HTTP
server points to the www.pix.com
,
not to the IP address of that host. This is important because we are about
to configure a different host to answer to www.pix.com
.
To configure reverse proxy caching for WMT:
1. Set the proxy.config.reverse_proxy.enabled variable in the records.config file on the
Media-IXT host to true.
2. Edit the remap.config file on Media-IXT, adding
map
and reverse_map rules. Note that the trailing
slashes in all of the rules are required.
First, the two HTTP map rules:
map http://10.10.10.10/ http://relay.pix.com/
map http://www.pix.com/ http://relay.pix.com/
Though very similar, the two HTTP map rules above are both necessary, because we don’t know whether
a client will address its HTTP request to the hostname or to the IP address of our website.