Problem with malware inspection and large video files.

Wed, 01 Jul 2009 07:26:35 Z

I'm using Beta 3 and have trouble downloading large video files when malware inspection is enabled. I have tried to uncheck the "Block files larger than 1000 MB" option, but it is still unstable. Specifically I try to download using the download manager ReGet. That does not work at all. If I open the file directly in Windows Media Player it works sometimes. If I disable malware inspection everything works as expected.

For this test I am trying to download the following Channel 9 video: http://mschnlnine.vo.llnwd.net/d1/ch9/3/1/7/5/7/4/ThisWeekC9June26_2MB_ch9.wmv

Is there a way to disable malware inspection for large files or spesific file types?

Hallis

Problem with malware inspection and large video files.

Wed, 01 Jul 2009 17:33:19 Z

i will test it in my lab and get back

Bala Natarajan [MSFT]| Sr. Support Escalation Engineer | CSS Security -TMG Beta support team | Email: bala.natarajan@microsoft.com | Office 425.704.4626 Bing it on bing.com

Problem with malware inspection and large video files.

Sat, 11 Jul 2009 17:55:04 Z

The size of the file is ~1GB so definitely adjusting or disabling the size is required.

The content type returned by the server is video/x-ms-wmv which is included in the fast trickling types. However, buffering and scanning have some overhead which may be noticeable, especially with slow download from the server. For example, if the download rate is exactly sufficient for playback (without EMP) adding accumulation and scanning will degrade it so that the player will need to pause the playback sometimes for buffering.

As for asusing a download manager – EMP removes the range headers to force downloading full files to make sure we dont by pass malware inspection .

Bala Natarajan [MSFT]| Sr. Support Escalation Engineer | CSS Security -TMG Beta support team | Email: bala.natarajan@microsoft.com | Office 425.704.4626 Bing it on bing.com