For wide-area networks (WANs), you must consider bandwidth constraints and latency issues. The PCoIP and Blast Extreme display protocols provided by VMware adapt to varying latency and bandwidth conditions.
If you use the RDP display protocol, you must have a WAN optimization product to accelerate applications for users in branch offices or small offices. With PCoIP and Blast Extreme, many WAN optimization techniques are built into the base protocol.
WAN optimization is valuable for TCP-based protocols such as RDP because these protocols require many handshakes between client and server. The latency of these handshakes can be quite large. WAN accelerators spoof replies to handshakes so that the latency of the network is hidden from the protocol. Because PCoIP and Blast Extreme are UDP-based, this form of WAN acceleration is unnecessary.
WAN accelerators also compress network traffic between client and server, but this compression is usually limited to 2:1 compression ratios. PCoIP and Blast Extreme have much higher compression ratios.
For information about the controls that you can use to adjust the way PCoIP and Blast Extreme consume bandwidth, see Optimization Controls Available with PCoIP and Blast Extreme.
Bandwidth Requirements for Various Types of Users
When determining minimum bandwidth requirements for PCoIP, plan with the following estimates:
100 to 150Kbps average bandwidth for a basic office productivity desktop: typical office applications with no video, no 3D graphics, and the default Windows and Horizon 7 settings.
50 to 100Kbps average bandwidth for an optimized office productivity desktop: typical office applications with no video, no 3D graphics, with Windows desktop settings optimized and Horizon 7 optimized.
400 to 600Kbps average bandwidth for virtual desktops utilizing multiple monitors, 3D, Aero, and Microsoft Office.
500Kbps to 1Mbps minimum peak bandwidth to provide headroom for bursts of display changes. In general, size your network using the average bandwidth, but consider peak bandwidth to accommodate bursts of imaging traffic associated with large screen changes.
2Mbps per simultaneous user running 480p video, depending upon the configured frame rate limit and the video type.
The estimate of 50 to 150Kbps per typical user is based on the assumption that all users are operating continuously and performing similar tasks over an 8- to 10- hour day. The 50Kbps bandwidth usage figure is from View Planner testing on a LAN with the Build-to-Lossless feature disabled. Situations may vary in that some users may be fairly inactive and consume almost no bandwidth, allowing more users per link. Therefore, these guidelines are intended to provide a starting point for more detailed bandwidth planning and testing.
The following example shows how to calculate the number of concurrent users at a branch or remote office that has a 1.5Mbps T1 line.
Branch or Remote Office Scenario
Users have basic Microsoft Office productivity applications, no video, no 3D graphics, and USB keyboards and mouse devices.
The bandwidth required per typical office user on Horizon 7 is from 50-150Kbps.
The T1 network capacity is 1.5Mbps.
Bandwidth utilization is 80 percent (.8 utilization factor).
Formula for Determining the Number of Users Supported
In the worst case, users require 150Kbps: (1.5Mbps*.8)/150Kbps = (1500*.8)/150 = 8 users
In the best case, users require 50Kbps: (1.5Mbps*.8)/50Kbps = (1500*.8)/50 = 24 users
This remote office can support between 8 and 24 concurrent users per T1 line with 1.5Mbps capacity.
You might require optimization of both Horizon 7 and Windows desktop settings to achieve this user density.