In our last newsletter we discussed some of the challenges associated with desktop virtualization as well as some of the technologies that have been developed to mitigate those challenges. In this newsletter we will continue that discussion and will highlight a potential synergy between server and desktop virtualization.
As noted in the last newsletter, the ICA and RDP protocols that are employed by many desktop virtualization solutions have limitations with graphics-intensive applications, 3D applications, and applications that require audio-video synchronization. A relatively recently developed display protocol that is intended to overcome those challenges is the PC-over-IP (PCoIP) protocol from the Teradici Corporation. PCoIP is a proprietary protocol that renders the graphics images on the host computer and transfers compressed pixel level data to the client device. PCoIP is compatible with zero clients. These are user display devices that have no operating system and no processor.
PCoIP is the display protocol used by the recently introduced VMware View 4 VDI product, which also supports RDP. A recently published document stated that, “To support the lower bandwidth typically available over a WAN, the minimum peak bandwidth required for a PCoIP connection has been reduced to 1Mbps.” It is important to realize that the 1Mbps required by PCoIP to support a single user represents a worst-case situation. However, the fact that in some cases each simultaneous user requires 1Mbps serves to underscore the fact that a significant amount of WAN bandwidth can be required to support desktop virtualization.
There are some interesting synergies between some of the various forms of virtualization. For example, the fact that most IT organizations have already deployed server virtualization makes it relatively easy and cost effective for them to implement virtualized WOCs. Since at least some WOCs can improve the performance of protocols such as ICA and RDP, the deployment of virtualized WOCs enables IT organizations to overcome some of the performance challenges that are associated with desktop virtualization. Unfortunately, however, PCoIP is encrypted and currently no WOC can improve its performance. Hopefully that will change in the near term.
Future newsletters will continue to explore both the challenges associated with virtualization as well as some of the emerging solutions. In the mean time we would like to point out that at the forthcoming Interop conference in New York City, Jim will be moderating a session entitled The Emergence of Virtualized Application Delivery Appliances and another entitled What Virtualization Means to the Branch Office. If you are going to be at Interop, you should plan on attending those sessions.
