VCAP-DTA Section 6 – Configure and Optimize View Display Protocols

Section 5 and dealing with ThinApp is now behind us, and now we turn to the networking stack. As you may know if you’ve done a bit of light reading, PCoIP is the protocol of choice for connecting to virtual desktops hosted by View. It’s a protocol proprietary to Teradici, so it’s not strictly an “in house” technology to VMware, but it has been in View for many years (since View 4, I think), so it’s a very mature and robust protocol.

One of the cool things about PCoIP is that it can do a level of auto tuning when there is congestion on the network. The VCAP-DTA blueprint has three sections for troubleshooting and configuration of PCoIP with just a couple of skills and abilities being measured per objective.

Objective 6.1 – Configure PCoIP and RDP for Varying Network Conditions

• Determine appropriate configuration parameters based on network performance – It’s typical that on a slow link you will want to tune PCoIP to be a little less aggressive with the bandwidth it uses. This can be done by using the PCoIP group policy template pcoip.adm which comes with the Connection Server in C:\Program Files\VMware\VMware View\Server\extras\GroupPolicyFiles folder. Import this template into your Group Policy Management MMC view and you are then able to configure PCoIP settings.
• Configure QoS and CoS settings for PCoIP

Once imported, go to Computer Configuration | Administrative Templates | Classic Administrative Templates | PCoIP Session Variables to configure PCoIP settings.

Typically, you will need to alter the following values to reduce bandwidth on a slow link :-

• Turn off Build-To-Lossless feature – Enabled
• Configure the maximum PCoIP session bandwidth – 10% less than WAN link speed 
• Configure PCoIP image quality levels –
  • Minimum Image Quality default is 50 and can be from 30-100, reduce this value to reduce bandwidth at the expense of user graphics experience. 
  • Maximum Initial Image Quality default is 90 and can be from 30-100. Reduce this value to reduce the initial screen “burst” as it is drawn.
  • Maxium Frame Rate  default is 30, this can be between 1-120 but if you reduce the value you reduce bandwidth but increase video jitter.
  • PCoIP session bandwidth floor by default is 0 (unset) but this value tells PCoIP the least amount of bandwidth it can expect for an end user and reserves this amount of bandwidth
  • Client image cache size policy is useful when the View Client end has some local storage it can cache to. For example, thin clients and regular PCs (tablets too, I guess) can cache regularly used images to help improve performance. This setting is probably useless on a zero client because it has no local storage, so watch out you don’t get a curveball there on the exam!