Multicast streaming from Guest OS has high jitter

[Kai]

Hi,

I have installed Windows 2003 Server 32-bit Standard Edition as Guest on top of either Centos 5.5 and Win7 hosts and both times, the system has the same problem. A multicast video stream has high jitter due to short playout pauses every couple of 100 msec. The setup is quite special - running Microsoft Mediaroom Personal Server, a test server setup for the Microsoft Mediaroom IPTV backend platform for developers. I checked several workarounds and nothing seems to work. looking at the performance of the host and client, there is only about 50% on the client and 30% of the host used (Intel Core i5 650 host, 6GB RAM, several settings for guest from 1 to 4 CPU and up to 3 GB of memory). There is no way to switch to 64 bit on the guest. Also there is no way to play the stream from another system, like the host - so far I figured it out - to be used as a workaround of this issue. So the stream is choppy, has macro blocks and pixelization when viewed on a TV (via a STB). I tested VMWare 7 and found the same problem. Haven't yet tried to use VLC server from various guests to see if it behaves the same. I suspected the disk - so a slow disk read as there are some peaks in the disk queue but those are minor and shouldn't be a major problem. Finally I suspect the timing/interrupt on the network interfaces (bridged).

Kai

[Kai]

addition: The stream itself is only 3 Mbps but played twice - once from a local loopback interface to the internal server and than replayed from there to the network interface.