In a View environment the PCoIP is usually the right choice and on a LAN works really well (see also the previous post about PCoIP and RDP differences). But on a wide-area networks (WANs)you have to consider some aspects to have a reasonable reactivity or to maximize the number of remote clients: you must consider bandwidth constraints and latency issues. The PCoIP display protocol provided by VMware adapts to varying latency and bandwidth conditions, but some optimization may be needed.
The best reference document is the VMware View 5 PCoIP Network Optimization Guide with a lot of useful information. But there are also:
- WAN Support and PCoIP
- Network Bandwidth Considerations
- VMware View PCoIP Network Sizing Guide
- VMware View PCoIP Zero Client Optimization Guide
- VMware View4 PCoIP
Bandwidth Requirements
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 VMware View 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 VMware View optimized.
- 400 to 600Kbps average bandwidth for virtual desktops utilizing multiple monitors, 3D, Aero, and Office 2010.
- 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.
Protocol tuning
Using the related GPO you can set some parameters in order to tune and optimized PCoIP:
- Build-to-lossless: you can also turn off the build-to-lossless feature altogether if instead of progressively building to perfect quality (lossless), you choose to build to perceptual lossless. This usually is a big enhancement for WAN users. Note that is turned on by default
- Client-Side Image Caching: you can adjust the size of the image cache on Windows and Linux client systems, from 50MB to 300MB (by default is 250MB). Image caching reduces the amount of display data that must be retransmitted.
- Image quality level: you can configure the image quality level and frame rate used during periods of network congestion. The quality level setting allows you to limit the initial quality of the changed regions of the display image. Unchanged regions of the image progressively build to a lossless (perfect) quality. You can adjust the frame rate from 1 to 120 frames per second. This control works well for static screen content that does not need to be updated or in situations where only a portion needs to be refreshed.
- Encryption: you can control which encryption algorithms are advertised by the PCoIP endpoint during session negotiation. By default, both Salsa20-256round12 and AES-128-GCM algorithms are available.
- Bandwidth allocation: with regard to session bandwidth, you can configure the maximum bandwidth, in kilobits per second, to correspond to the type of network connection, such as a 4Mbit/s Internet connection. The bandwidth includes all imaging, audio, virtual channel, USB, and control PCoIP traffic. You can also configure a lower limit, in kilobits per second, for the bandwidth that is reserved for the session, so that a user does not have to wait for bandwidth to become available. You can specify the maximum bandwidth that can be used for audio (sound playback) in a PCoIP session.
- MTU: You can specify the Maximum Transmission Unit (MTU) size for UDP packets for a PCoIP session, from 500 to 1500 bytes.
VPN Compatibility
PCoIP is already encrypted and can work (with some limits on the required ports) with a VMware Security Server so usually a VPN is not required. But if you really need to use a VPN you can use those old reference guides:
- VMware View and Juniper Networks SA Servers SSL VPN Solution
- VMware View and F5 BIG-IP SSL VPN Solution
- VMware View and Cisco Adaptive Security Appliances (ASA) SSL VPN Solution
WAN Accelerator
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, many WAN optimization techniques are built into the base protocol and usually a WAN accelerator or optimizer is not required (and may be not useful at all).
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 is 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 is able to provide compression ratios of up to 100:1 for images and audio.
But there are some specific note for some product vendors: