Dell Precision R5400 Remote Access Device: Networking Considerations - Page 6

The PCoIP Host Processor and PCoIP Portal Processor both generate network traffic between the centralized datacenter and the user desktop. To ensure desktop responsiveness, this process of compression, transmission, and rebuilding the desktop occurs in a very short time, typically less than 10ms. PCoIP Network Traffic PCoIP network traffic contains traffic for image data, USB and HD audio peripheral bridging, and system management. The traffic profile is dominated by the downstream (host to portal) compressed image data. USB and audio-generated traffic typically have significantly lower bandwidth requirements than the image data. There is a negligible amount of bandwidth required for system management traffic. Imaging network bandwidth is only consumed during screen changes (opening/moving a window, high resolution video, etc.). Most office application scenarios are characterized by long periods with no screen changes, which result in long periods of virtually no network traffic. Overall bandwidth requirements are therefore based primarily on applications and usage scenarios, as well as on display resolution. Network Recommendations for PCoIP Deployments Today's enterprise networks have evolved to the point where a full-scale PCoIP deployment is readily achievable and can fit within existing switched 100Mb/s workgroup/datacenter infrastructures. In a modern enterprise network, the available bandwidth is generally the same regardless of the direction from the datacenter. The dominant traffic in a PCoIP deployment is downstream (host to portal) so network sizing and requirements are specified on the link rates in the downstream direction. The following procedure allows IT administrators to generate a network configuration which can guarantee an excellent user experience for all the users on the PCoIP system. This procedure is a conservative estimate which guarantees a certain experience in the worst-case usage scenario where all active users are concurrently doing an operation which requires high imaging bandwidth (dragging windows or watching multimedia). This procedure is appropriate for deployments where the required amount of bandwidth is generally available, such as in LAN and campus networks. In cases where the required bandwidth is not available, the PCoIP host and portal pair will continue to operate by dynamically adjusting the network traffic generation to fit within the available network bandwidth. This is done in such a way to minimize any degradation in the user experience. In order to determine the network resources required for a PCoIP system deployment, IT administrators should consider the following steps: 1. Segment the user base by applications and display (Table 1). 2. Determine the per-user bandwidth allocation for each user type (see Table 3). 3. Determine the number of active users contributing to every link. 4. Determine link planning bandwidth for each network link. 5. Set the device bandwidth target for each PCoIP Host. Definitions Some key network bandwidth settings and considerations are defined below: Planning Bandwidth - defines the per-user bandwidth that will deliver the minimum desirable user experience, as defined by that user's profile. The planning bandwidth includes requirements for all traffic types, including display image, USB, and audio data traffic. Table 3 provides conservative guidelines for the Planning Bandwidth for various user categories. Link Planning Bandwidth - defines the bandwidth required for a certain network link. It is defined as the sum of all the Planning Bandwidth's of all the users who will be actively using the link at any one time. TER0806005 Issue 1 6