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Microsoft RDP Bandwidth Whitepaper

Tuesday, 04 November 2008 by Michel Roth

I have seen the importance of proper loadtesting been underestimated in SBC as well as VDI environments for more times than I care for This is why I was so happy to see this whitepaper by Microsoft titled "RDP 6.1 Performance White Paper". However I think there are more than one "but" and "maybe". Let me be the first to say that I love whitepapers that look into something as bandwidth requirements in remote display protocols. I have seen a lot of people underestimate the importance of bandwidth requirements. Examples are newer protocols that work fine on a network that has 10Gig networks but fail to deliver on slower (WAN) networks. The RDP, Quest's implementation of RDP and ICA protocol are true thin protocols that actually work over a WAN.
This whitepaper takes a look at the different measures that Microsoft took in the RDP implementation of Windows Server 2008 and Windows Vista and how they save bandwidth.

The thing that bugs me is that the most important factor in a good loadtest/benchmarking test, the user actions simulated, are a bit oversimplified in this whitepaper. The user actions that were simulated in this whitepaper are:

•   Executive PPT Scenario. This scenario emulates a user presenting 28 high-fidelity slides by using Microsoft® Office PowerPoint® 2007. The slides contain images, transitions, and backgrounds with color gradient. The user spends about 20 seconds on each slide.

•   Simple PPT Scenario. This scenario emulates a user creating and presenting content by using PowerPoint 2007. The slides in this scenario are more text-intensive than those in the executive PowerPoint scenario and have a plain background. Some of the slides contain digital photo images.

•   Typing and Scrolling Scenario. This scenario emulates a user scrolling through a 10-page document and typing 8 pages in another document by using Microsoft Office Word 2007. The user types at 35 words per minute and scrolls at about 2 pages per minute. The user also moves and resizes the windows as he moves between the two documents.

•   Scrolling Scenario. This scenario emulates a user scrolling through a 275-page Word 2007 document that contains several Microsoft Office Visio® 2007 (data-flow) diagrams and embedded tables. The user scrolls at about 2 pages per minute.

•   Internet Explorer Scenario. This scenario emulates a user browsing the Web by using Internet Explorer 7. The user browses and scrolls through multiple Web pages that contain a mix of text, natural images, and some schematic diagrams. The Web pages are stored on the local disk drive of the terminal server to avoid errors due to varying load times.

Of course I know where this whitepaper is coming from (literally) but I would have like to see more reallife examples like reading a PDF (no not XPS) and browsing a "real" website like espn.com or Youtube. Outlook is also one that should not be forgotten as far as I am concerned.

Another thought that popped into my mind is that, in order to get some of the bandwidth savings mentioned in the whitepaper, you would need a Vista to Vista connection. To be honest, I have not seen that being done a lot.

All that being said. It certainly is a absolutely valuable whitepaper to read . As a final note I would like to point our that it is possible to get a better user experience over RDP by using Quest's EOP (full disclosure - I work for Quest) while using about 8 times less bandwidth than the best performing compression in the "normal" RDP protocol 6.1.