Enabling Cache/Proxy Features
Managing network
bandwidth and server resources when supporting large numbers of users
can be difficult when using only a single Windows Media Services server.
The server itself can often become a bottleneck and can lead to
performance problems for clients. Additionally, the failure of the
server can result in a loss of access to audio and video data. To
address these issues, you can use the Windows Media Services Cache/Proxy
features.
Caching and proxying are
methods by which Windows Media Services can relay streamed information
from one publishing point to users who need it. Caching refers to when a
Windows Media Services copies content from the origin server and stores
it locally. The caching server is responsible for obtaining the data
from the source and sending it directly to the client. A proxy
configuration is used to have multiple computers that are running
Windows Media Services send requests to other streaming media servers. Figure 34 provides an example of a typical server configuration.
In this diagram, the
origin server is providing access directly only to the distribution
servers. The distribution servers, in turn, can then send streamed
information to the clients that require it. This reduces the network and
processing load on the primary Windows Media Services server and
enables users to connect to servers located optimally based on their
network configuration.
Enabling Cache/Proxy Settings
By
default, Cache/Proxy Management is disabled for new Streaming Media
Services installations. To enable this feature for a server, open the
Windows Media Services console, and select the server object. Then,
select the Properties tab and the Cache/Proxy Management category.
Right-click the WMS Cache Proxy plug-in, and select Enable. You can also
double-click the WMS Cache Proxy plug-in to access configuration
options for the cache and proxy features.
The General tab enables you to select which protocol is preferred for streaming media between an origin server and the cache/proxy server. The default setting is to use whichever protocol the client has requested.
Tip
When
considering the features of Windows Media Services, a single server can
serve multiple roles. For example, it can provide access to both
on-demand and live broadcast publishing points while it is also proxying
requests and caching content for other servers. For the sake of
simplicity, this lesson refers to “source servers” and “proxy/cache
servers.” Depending on your network design or requirements presented on
the exam, you might want to configure the same server with all these
functions.