Comparing VDI to DaaS

There are two primary Virtual Desktop solutions; Virtual Desktop Infrastructure (VDI) and Cloud-based Desktop-as-a-Service (DaaS).   Both solutions provide users with a full desktop and/or a streaming application or applications. If the VDI or DaaS system functions and performs within specifications, end-users would not know the difference. This article provides an overview of VDI and DaaS.

The question on many technical leaders’ minds is, “Should I implement VDI, DaaS or stay with physical PCs?” The solution you choose should meet validated requirements, stay within allocated costs and be supportable with projected resources (personnel). Since IT is a Cost Center, it is critical to make the right decision.

Virtual Desktop Infrastructure (VDI): This technology is used to provide a full desktop or streaming application from servers and services deployed within the company’s physical datacenter. It could be VMware Horizon, Citrix, Nutanix, flexVDI, etc. Several other smaller companies provide VDI. However, be careful which VDI solution you choose.  You get what you pay for.   

  • VDI provides the customer complete control of the infrastructure (network, systems, support services) and the VDI application. This could be a Pro or Con depending on your requirements.  If the company requires complete control and has the required staff to deploy and maintain the solution, VDI would be a good choice. Beware, VDI is a complex technology. Here is a VMware Horizon 8 example solution working from bottom up.
    • Nutanix HCI servers configured as clusters provide the physical support infrastructure. Support services and/or Nutanix engineers required to maintain the Nutanix infrastructure.   
    • VMware ESXI installed and configured on each Nutanix host providing Hypervisor services.  Support services and/or VMware engineers required to maintain and update the ESXI infrastructure.  
    • Deploy VMware vCenter and create VMware Cluster. Support services and/or VMware engineers required to install, configure, and maintain the vCenter Clusters.
    • Deploy VMware Horizon 8.  Support services and/or VMware engineers required to install, configure, and maintain the Horizon 8 environment.
    • Build a Windows 11 Master Image. This is the source image for all Virtual Desktops. Must identify Desktop Engineers and admins to build and maintain the Master Image.
    • Provide a networking infrastructure. This is normally a vlan or vlans dedicated to VDI traffic. PCoIP (PC over IP) protocol is UDP over port 4172.  VMware also provides a vendor specific protocol called Blast Extreme. This protocol improves the end-user experience and it only works with VMware Horizon. I’ll write a comparison blog article in the future.  The VDI network should use QoS to support projected Bandwidth and reduce latency, jitter and packet loss.  PCoIP only transmits video pixels. As the users time in session progresses, only the pixels that change are transmitted. UDP is much more efficient than TCP supporting streaming applications. Identify Network Admins and Engineers to ensure the configuration is properly deployed and maintained.
    • Authentication of the user is required.  Normally this is set using multifactor authentication. M2F could be configured using RSA SecureID, YubiKeys, Smart Cards and authentication applications integrated with Windows Active Directory. There are many M2F solutions on the market.
    • Service Desk must be trained to troubleshoot VDI issues.

Diagram of a high-level VMware VDI solution

Desktop-as-a-Service (DaaS). This technology is similar to VDI. However, the primary difference is the application and virtual machines are sourced from and reside in the Cloud. Microsoft Azure Virtual Desktop (AVD), Amazon Web Services (AWS) Workspaces, VMware Horizon Cloud, and Nutanix Frame are some more prominent DaaS players. But, again, there are many other smaller and not as well-known providers of DaaS solutions.

  • DaaS’s primary claim to fame is its ability to support small and large users environments with the least amount of complexity. This is achieved through outsourcing administrative support and all hardware requirements and most application support. This provides the flexibility to purchase only what you need and maintain stability by having the provider meet Service Level Agreements (SLA).    This is Microsoft Azure Virtual Desktop service breakout of what they support and what the customer would support. Basically, you control what a user can access and how the user interacts with the company data. Microsoft manages the hardware and services.

The line is getting blurred between VDI and DaaS.  You can deploy VMware Horizon 8 (VDI) in AWS or Azure using VMware Cloud (VMC). VMC uses the provider cloud resources to build a VMware vCenter Cluster. Using the VMC, you can deploy Horizon 8 on-prem VDI into cloud base resources.  VMware refers to this as Cloud VDI. If you are already a VMware shop, the learning curve would be negligible.  If you have Horizon 8 deployed onsite, you can deploy another instance in the Cloud and use it as a backup if the primary fails. VMware refers to this as a “POD” architecture. This solution will save you from buying additional physical hardware, and if the performance meets requirements, users can be migrated to the Cloud VDI.

The last area to be discussed is keeping your present physical PCs.  Your company may be functioning fine with PCs and Laptops. It depends on validating requirements and cost considerations. The upfront cost may be too high, or you may not have a valid need for VDI or DaaS.

We covered several concepts in this article.  I would suggest you perform due diligence before deciding.

Author: Chet Camlin

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