When using windows media redirection and watching a live multicast stream, client side fetching can fail and receiver may fall back to using server side fetching, This can lead to increased network traffic in the environment.

An easy way to notice this is that the stream will initially take a long time to load when the URL is clicked.
This can also be verified using HDX monitor tool.

Create the following registry key on the endpoint client running receiver.

Path: HKEY_CURRENT_USER\SOFTWARE\Citrix\HDXMediastream
Type: REG_DWORD
Name: CSFPreferredFramework
Data: 1

Other values
0: Default (Media Foundation)
1: DirectShow
2: Media Foundation

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Problem Cause

By default Citrix Receiver will attempt to render a URL by using media foundation first and directshow second. URL's pointing to a multicast stream typically point to a file extension of type .nsc and always want to attempt rendering with directshow first. When this issue manifests, attempting to render the multicast stream via media foundation first, the CREATE_CONTEXT message from the VDA was timing out and the render stream falls back to the server side. Applying the registry key will allow the media stream to render using directshow first.

Note: Improvements have been added to later versions of receiver (receiver 4.7) and this workaround should not be required.