One of the common questions that Citrix customers implementing XenDesktop 4 for Branch Offices ask is “How much Bandwidth is required to deliver XenDesktop 4?” Even though the typical answer to such a specific question is “It depends” and it is based on available bandwidth, latency, WAN congestion and user/application activities, customers still need some sort of guide or range to help them plan for a large scale XenDesktop deployment. So, I am happy to announce that Citrix Consulting Solutions recently performed extensive testing to provide guidance to customers to help determine how much Bandwidth is required for delivering XenDesktop 4 over the WAN. The report Performance Assessment and Bandwidth Analysis for Delivering XenDesktop to Branch Offices aims to provide customers with bandwidth requirement guidance for standard user workflows such as Office 2007, internet browsing, printing and video executed in a XenDesktop virtual desktop delivered over WAN. Along with the guidance for native XenDesktop bandwidth requirements, Citrix Consulting also integrated Citrix Branch Repeater with XenDesktop to utilize its WAN optimization techniques for optimizing XenDesktop connections. Citrix Branch Repeater provides significant reduction in the amount of bandwidth required to deliver XenDesktop over a WAN and hence provides customers with a cost effective alternative to a WAN upgrade.

Let me give you a brief snapshot of the testing methodology and results of this Citrix Solution Center project. We leveraged Login VSI Pro, a benchmarking tool designed for SBC and VDI solutions, to execute our standardized Office workflows. By using this publically accessible tool, customers can now perform similar in-house tests to obtain more specific results for their customized workflows and answer the “it depends” question. Login VSI Pro was also used to launch simultaneous XenDesktop connections over a simulated WAN to determine the average bandwidth required for each workflow under utilized WAN conditions. This is important in performing accurate bandwidth requirement measurements as the underlying ICA protocol optimizes itself in a utilized WAN scenario. We also monitored end user experience to identify any degradation in performance while increasing the number of simultaneous XenDesktop connections.

The following graph provides a summary of the Average Bandwidth consumed for native Citrix XenDesktop and the performance benefits gained when Citrix Branch Repeater is integrated into the Citrix XenDesktop solution. All the numbers shown below are for the respective workflows over a WAN connection of 1.5 Mbps, 80ms latency and 1% packet loss (with the exception of the HD video which required a 10Mbps connection based on the high data rate of the video).

The testing results show that Citrix Branch Repeater provides dramatic bandwidth savings allowing customers to add up to twice the number of users executing similar workflows on existing WAN connection. Now customers can accelerate the ROI in their XenDesktop 4.0 investments while providing a rich desktop experience to branch office users. For more details on the testing approach and results please refer to the document here. Also for customers interested in performing similar testing specific to their implementation, please contact Citrix Consulting Services for assistance or email me with specific questions or comments at