Microsoft Whitepaper: Reference Architecture for DaaS (Service Providers)

This document defines a set of architectural blocks for creating a multitenant, hosted Windows desktop and application service. The primary goal is to enable hosting providers to create secure, scalable, and reliable desktop hosting solution offers for small and medium-sized organizations with up to 1500 users.

The intended target for this reference architecture are hosting providers who deliver cloud services via the Microsoft Service Provider Licensing Agreement (SPLA) program. To deliver a desktop hosting solution via Microsoft’s SPLA program, hosting partners leverage Windows Server® and the Windows Desktop Experience feature to deliver Windows users an application experience that is familiar to business users and consumers. Although Windows 8, Windows 7, and earlier Windows client versions are not licensed for SPLA, the Desktop Experience feature in Windows Server 2012 provides a similar user experience and application support. Hosting providers can leverage the virtualization rights in Windows Server Datacenter edition to minimize infrastructure licensing costs as the hosting providers scale the number of users.

The scope of this document is limited to:

• Architectural design guidance for a desktop hosting service.
  Detailed information, such as deployment procedures, performance, and capacity planning is explained in separate documents. For more general guidance about the fabric and infrastructure, see the following documents:
  Infrastructure-as-a-Service Product Line Architecture Fabric Architecture Guide
  Infrastructure-as-a-Service Product Line Architecture Fabric Management Architecture Guide
• Session-based desktops, RemoteApp applications, and server-based personal desktops that use Windows Server 2012 Remote Desktop Session Host (RD Session Host).
  Windows client-based virtual desktop infrastructures are not covered because there is no Service Provider License Agreement (SPLA) for Windows client operating systems. Windows Server-based virtual desktop infrastructures are allowed under the SPLA, and Windows client-based virtual desktop infrastructures are allowed on dedicated hardware with end-customer licenses in certain scenarios. However, client-based virtual desktop infrastructures are out-of-scope for this document.
• Microsoft® products and features, primarily Windows Server 2012 and System Center 2012 Service Pack 1 (SP1) Virtual Machine Manager (VMM).
  In a few cases, this document identifies components that must be provided by a third party to complete the desktop hosting solution, but deeper architectural guidance is not provided for third-party components.
• Virtualized service workloads
  To maximize deployment flexibility, all service workloads are run in Hyper-V® guest partitions, also known as virtual machines.
• High availability provided by Hyper-V in a failover cluster.
  Additional levels of high availability can be provided by guest clustering, but that is out-of-scope for this document. For more information about host and guest clustering, see the following topics:
  Your Hyper-V Hosts and Clustering
  Super-fast Failovers with Virtual Machine Guest Clustering
• Desktop hosting services for tenants ranging in size from 5 to 1500 users.
  For larger tenants, this architecture may need to be modified to provide adequate performance.

Source: http://www.microsoft.com/en-us/download/details.aspx?id=39285