I have just made available the first release of my VDI Display Protocol Calculator. This calculator complement the online VDI Calculator. The original VDI Calculator  that is a great tool in helping architects and administrators to size deployments.

The main idea behind this new calculator is to quickly provide a ballpark figure of network bandwidth required to support a VDI deployment or roll-out. The calculator will point you to the most appropriate display protocol to be used and will also provide network bandwidth figures.

At this stage PCoIP and RDP are the protocols of choice, but in the future additional display protocols may be added. Given that both display protocols have dynamic bandwidth utilisation, all pre-defined numbers utilised in this calculator are official data provided by Teradici, VMware or Microsoft. However, because these pre-canned numbers do not not apply to all deployments I have also added a custom field where you can enter your own values.

Some important notes to be observed:

Ensure guaranteed Network Utilisation bandwidth for PCoIP traffic during congestion. In general, set PCoIP traffic to have 80% of the remaining bandwidth after the higher priority traffic is allocated. E.g. consider a network that guarantees 20% of a link bandwidth for critical traffic such as VoIP, PCoIP should be set to receive 80% of the remaining bandwidth. This allows other protocols such as file transfers or web traffic to always be able to transfer some traffic, without starving the PCoIP sessions.

User Profile bandwidth defines the per-user bandwidth that will deliver the minimum desirable user experience, as defined by that user’s profile. The User Profile includes requirements for all traffic types, including display image, USB, and audio data traffic. The Total Bandwidth is defined as the sum of all the User Profile of all the users who will be actively using the link at any one time.

The default settings used by the calculator are as follows:

The Available Bandwidth is the capacity of the network to forward packets, described in bits per second. Networks may have any number of capacity constrictions, including link-rates between switches, or internal switching limits of the switches themselves.

Bandwidth Offset

Not much discussed is how display protocols are often over-provisioned. With exception to very specific use cases where there is multicast involved its not common to see workloads where all users simultaneously fully utilise the network bandwidth allocated to their User Profile. The non-utilised bandwidth accumulates and the higher the number of users are, more free bandwidth should be available. I call it Bandwidth Offset.

Figure 1 demonstrate a linear bandwidth sizing based on 200 users and 200 Kbps.

Figure 2 demonstrate a non-linear bandwidth sizing based on same numbers but using a x offset number for each y users. In this case it could be 10% or 20% for each 100 users.

Unfortunately this feature is not yet available in this first release of the calculator and I will discuss it in detail in a later post. However I have already a beta version to be released soon that will include calculation of the real bandwidth based on Bandwidth Offset.

This calculator is release 1.0 and I appreciate constructive feedbacks on how to improve it.

To access the calculator go to https://myvirtualcloud.net/?page_id=1562 or select VDI Protocol Calculator from the Top Menu.