Take a look at (below) the MediaCacheSource from an EC2 instance that enables the "vods3" application.
Code:
<MediaCacheSource>
<Name>amazons3</Name>
<BasePath>http://s3.amazonaws.com/</BasePath>
<Prefix>amazons3/</Prefix>
<BaseClass>com.wowza.wms.plugin.mediacache.impl.MediaCacheItemHTTPImpl</BaseClass>
<ReaderClass></ReaderClass>
<DefaultBlockSize>262144</DefaultBlockSize>
<MaxTimeToLive>1200000</MaxTimeToLive>
<MinTimeToLive>600000</MinTimeToLive>
<ReadAhead>true</ReadAhead>
<ReadAheadThreshold>50</ReadAheadThreshold>
<IsPassThru>false</IsPassThru>
<Properties>
<Property>
<Name>maxPoolSize</Name>
<Value>25</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>httpReadTimeout</Name>
<Value>6000</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>httpConnectionTimeout</Name>
<Value>6000</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>httpReadRetries</Name>
<Value>3</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>httpSendBufferSize</Name>
<Value>8000</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>httpReceiveBufferSize</Name>
<Value>65000</Value>
<Type>Integer</Type>
</Property>
<Property>
<Name>isAmazonS3</Name>
<Value>true</Value>
<Type>Boolean</Type>
</Property>
<Property>
<Name>s3BucketNameInDomain</Name>
<Value>true</Value>
<Type>Boolean</Type>
</Property>
<!-- Uncomment and set properties if streaming from S3 authenticated -->
<!--
<Property>
<Name>awsAccessKeyId</Name>
<Value></Value>
</Property>
<Property>
<Name>awsSecretAccessKey</Name>
<Value></Value>
</Property>
-->
</Properties>
</MediaCacheSource>
Richard