August 29, 2022 Author:  Nagaraj ManoliSpecial thanks:  Kireeti Valicherla, Swaroop JV, Alan Goldman, Derek Thorslund, Steve Beals

Reference Architecture: Citrix DaaS Standard for Azure

Audience

This document is intended for technical professionals, IT decision-makers, partners, and system-integrators. This document also allows the administrator to explore, and adopt Citrix DaaS Standard for Azure to provide cloud-based workspaces to their employees. The reader must have a basic understanding of Citrix products, Citrix Cloud, and Microsoft® Azure services.

Objective of this document

This document comprises of a technical overview, architectural concepts, and adoption methodology on Citrix DaaS Standard for Azure. Multiple use cases on different verticals with conceptual architecture are also included to allow readers to understand and formulate the cloud-based virtual desktop solution.

Introduction to Citrix DaaS Standard for Azure

Citrix DaaS Standard for Azure is a cloud-based virtual apps and desktops solution. It enables businesses to deliver cloud-hosted virtual apps and desktops to any device, over the network, from any location. The operating system runs inside virtual machines on the Azure public cloud. All the necessary infrastructure (IaaS) support is provided from Citrix. Citrix managed Azure subscription is owned and managed by Citrix where Virtual Delivery Agents (VDAs) are running. The virtual apps and desktops are presented over the secured network to a customer’s endpoint devices where end-users access them through the Citrix Workspace app or a web browser.

The Citrix DaaS Standard architecture is divided up into multiple segments. All segments flow together to create a complete, end-to-end cloud-based virtual desktop solution for an organization.

• Users segment- This section describes the end-user environment and end-point devices that are used to connect to resources. This section covers the end-point devices and Citrix Workspace app.

• Access segment- This section describes external connectivity to devices in the user segment. This section covers the Citrix Gateway service and Workspace configuration details.

• Control segment- This section describes components used to support the rest of the environment, which includes site design for the Citrix Cloud service, image management, and monitoring of Citrix DaaS Standard.

• Resource segment- This section captures information for the users personalization, applications, and images for the Citrix DaaS Standard environment.

• Platform segment- This section describes the cloud platform used to provision catalogs. Citrix Managed Azure Platform is based on Microsoft® Azure platform for Citrix VDAs, that is completely managed by Citrix. Customer-managed Azure subscriptions are used to provide hybrid connectivity to additional resources as required.

• Operations segment- This section contains customer-managed components such as Windows Active Directory service, Azure Active Directory, file servers, and Windows license servers. It is possible to provision file servers and license servers on customer-managed Azure subscription or in a customer data center with hybrid connectivity between Azure to an on-premises data center.

The layered picture gives a holistic view of the Citrix DaaS Standard services. The details and internal architectures of Citrix Managed Azure Platform, hybrid connectivity, image management approach, and multiple deployment methodologies are explained in upcoming sections.

Citrix DaaS Standard for Azure and traditional desktop solution

Organizations typically adopt virtual desktop solutions based on their business needs. As companies expand their global footprint and increase productivity, IT is often left with the challenge to meet the growing demands and use cases. Organizations have started to adopt digital workspace solutions based on traditional desktop solutions. The virtual desktop solution has been around for a long time and traditionally was the only way to run a virtual desktop. This is cost-effective for companies that have a large employee base in a single region or geographic location.

The traditional virtual desktop solution requires substantial support from IT professionals. This includes customization of desktops, maintaining efficiency with the latest updates, assuring solid connectivity, and providing great user experience.

In a traditional virtual desktop infrastructure solution, IT administrators are responsible for the management of the implementations. Organizations often require a significant investment in capex for infrastructure. Apart from this process, the additional investment in securing the infrastructure must be in place, for example, localized threat detection solutions must be implemented to avoid any data breaches.

Most of the cloud service providers have observed these challenges faced by customers. To overcome this problem many leading vendors introduced Desktop as a Service (DaaS) to the market. DaaS solutions allow customers to quickly realize the benefits of VDI, switch from a capex to opex model, and reduce the required ongoing management effort. Citrix, one of the pioneers in the desktop virtualization field, has introduced the DaaS solution called “Citrix DaaS Standard for Azure.”

Citrix DaaS Standard is similar to a VDI solution. It offers the same user experience, and flexibility with greater visibility to the infrastructure and overcomes initial deployment haul and investments. Citrix DaaS Standard differs from the traditional desktop solution because instead of hosting desktops in an on-premises data center or even a public cloud location with full infrastructure management required, Citrix DaaS Standard uses a cloud-based back end from the Microsoft® Azure cloud platform while greatly simplifying setup and management tasks in a simple, turnkey solution.

Citrix DaaS Standard requires only a minimal investment to start, which is a good fit for small and medium-sized businesses. The organization does not need to invest in VDI or virtualization experts - Citrix DaaS Standard is well-suited for IT generalists to handle.

The following table compares the Citrix DaaS Standard solution with a traditional virtual desktop solution:

Benefits	Citrix DaaS Standard	Traditional virtual desktop solution
Simplified virtual desktop implementation	Easy to deploy	Moderate deployment steps
Centralized desktop management	Complete centralized management solution	Multiple silos of infrastructure to manage
Data security	Reduced attack surface with key back-end maintained by Citrix	Additional considerations for ongoing optimal security
Issue resolution and recovery	Simplified	Moderate with sturdy IT resources
Capex ($)	Upfront investments not required	Moderate to the significant investment required
Opex ($)	Minimal deployment cost	Moderate for small scale deployment
Geographic coverage (workloads)	Supports multiple Geos across Azure regions	Bound to data center locations
Complexity and risk	Minimal	Moderate
Pay-as-you-go model	Highly applicable	Not applicable
Skilled resource requirement	Basic IT generalists	Skilled specialists often required

Why organizations adopt a Citrix DaaS Standard for Azure solution

Many organizations desire to benefit from this era of the digital workspace. Their workforce expects a different set of work culture which means accessing their work from anywhere on any device at any time. Meanwhile, management wants to control IT spending. Cloud-based virtual apps and desktop solutions are the better choices when companies are looking for a cost-effective, simple solution to securely deliver the apps and desktops to their workforce.

Citrix DaaS Standard is a viable solution for customers looking for centralized management with standardized virtual desktop infrastructure. In the era of the digital workspace, Citrix enables an organization to deliver do-it-yourself cloud-based apps and desktop.

The above diagram shows a high-level skeleton view for Citrix DaaS Standard. The control plane is hosted in Citrix Cloud and all the resources are provisioned on the Microsoft® Azure platform which is managed by Citrix. Citrix DaaS Standard customers have an option to choose the workload region (supported by Citrix) depending on their requirements.

Citrix DaaS Standard offers many advantages to IT by simplifying operations and delivering Windows desktops and apps securely to its workforce:

• Azure Virtual Desktop (AVD) instances hosted on a Citrix Managed Azure platform

• Superior user experience which enables users to collaborate with their work culture

• Simplified management and monitoring through Citrix Cloud

• Secure remote access with multifactor authentication

• Citrix Virtual Delivery Agents (VDAs) running within the Microsoft® Azure platform (Citrix Managed). The administrator can bring multiple Azure services including ExpressRoute, VPN services, Azure Files from customer-managed Azure subscription.

Citrix DaaS Standard for Azure use cases

Citrix DaaS Standard has the ability to manage unforeseen business shifts in IT infrastructure on different vertical segments. Citrix DaaS Standard gives liberty to businesses from the complex act of implementation and management of the IT infrastructure. Complexity in terms of purchasing, supporting, upgrading, and most important is security.

In this section, some of the useful and constructive use cases on different verticals are discussed.

Citrix DaaS Standard for Azure in Education services

Today most of the universities are transforming their learning paths and skill development engagements. Students and lecturers must be there at the campus to access software and services required for their studies. This process may hamper or decrease overall time efficiency. With the current IT infrastructures, many education services are facing the challenges to meet the demand. Usually IT organizations purchase and build out an infrastructure that sits unused much of the year.

To overcome all the challenges faced by universities, Citrix has seen the opportunity to improve student productivity and engagements by hosting all necessary software and tools on the Citrix DaaS Standard service. Students can access their necessary resources anytime, anywhere, and from any device.

The above diagram shows a conceptual Citrix DaaS Standard usage in universities. The administrator has to create the catalogs for individual machine types. The Student catalog uses a non-domain joined catalog. The administrator has to install the required application during the master image creation. For the Lecturers catalog, the separate image can be used to provision the VDAs which are domain joined desktops. If the university is already utilizing Azure AD with Office 365, no VNet peering or customer-managed components are necessary.

Here multiple catalogs share a resource location and virtual network. A virtual network is a unique per-connection for domain-joined catalogs, and per region for non-domain joined catalogs.

Healthcare Solution using Citrix DaaS Standard for Azure

In healthcare, field professionals have a pressing need to access real-time patient data and applications remotely and from multiple devices. Today many healthcare institutes are facing regulatory burdens and shrinking IT budgets which made their hands tied to traditional desktop technology. Citrix DaaS Standard offers a straightforward way to increase technological presence without a major refurbishment of a company’s systems and processes.

Overall cost reduction is the top challenge. Citrix DaaS Standard generally saves money and time and there is no cost associated with the implementations. The above diagram shows the healthcare institutes using Citrix DaaS Standard in multiple resource locations and providing anywhere access, centralized management, and flexible working are the key drivers for this solution.

Key benefits of using Citrix DaaS Standard in healthcare institutes:

• Access file and patient’s data from anywhere

• There is no cost associated with the upgrading and managing the IT infrastructure

• Easier data backups and recovery

• Flexible and predictable scale

• Security and compliance

• Focus on the primary mission, delivering the best care to patients

Citrix DaaS Standard for Azure for the Logistic industry

The logistic company workforce always faces challenges in accessing the mission-critical data from anywhere and anytime. This data includes an inventory list from the warehouse, tracking orders, billing information, and so on. These kinds of circumstances always recede productivity.

By hosting their desktops and applications in the Citrix DaaS Standard, customers can focus on their core business without having to waste time and money on procurement and managing the infrastructure.

Key benefits of adopting Citrix DaaS Standard include:

• Low TCO

• Mobility

• Scalability

• Security

• Centralized Management

Mergers and Acquisitions

Today there are huge barriers when brining two separate companies’ assets into one. Mergers and acquisitions take place in today’s business world to grow and expand the business market. But the real challenges are faced when merging IT infrastructure.

Positioning the IT infrastructure of two separate entities needs future infrastructure planning, utilization, and the management of legacy applications with their infrastructures.

In the case organizations have multiple forests and multiple exchange servers, it is more cumbersome to consolidate.

The above diagram depicts the multiple Active Directory forest present on-premises when the merger or acquisitions take place. When organizations have multiple forests, all forests must be reachable by a single Azure AD Connect sync server. It is not necessary to join the server to a domain. In a case where it is necessary to reach all forests, the administrator can place the server in a perimeter network such as the DMZ. The goal of this solution is that a user is represented only once in Azure AD.

The advantage of Citrix DaaS Standard is, the administrator can easily consolidate two forests with a single Azure AD. The new demand and requirement of desktops are easily provisioned on Citrix DaaS Standard. This solution enhances user productivity.

There are other topologies available for Azure AD Connect and those are:

• Multiple forests, single sync server, users are represented in only one directory

• Multiple forests: full mesh with optional GAL Sync

• Multiple forests: account-resource forest

For more information on different topologies for Azure AD Connect refer to the following link
.

Non-Domain Joined Desktops for DevOps and seasonal workers

In Citrix DaaS Standard a virtual desktop can be domain joined or non-domain joined. When there is an urgent requirement to involve third-party developers in the project it is hard to provide a desktop with reliable connectivity. For example, a seasonal worker or contractor whose involvement in the project is as required as organization employees. Apart from this task, the administrator has to make sure that they are accessing resources securely.

The above diagram shows a non-domain-joined desktop provisioned for contractors and any dev-ops worker. The administrator creates a catalog for the dev-ops team and provisions a desktop with a necessary application that is not joined to the corporate domain. The administrator can provide or use Azure multifactor authentication to add one more layer of security.

The end-user has to access their desktop through Citrix Workspace app using URL the provided by the Citrix administrator.

Technical Overview of Citrix DaaS Standard for Azure architecture

Citrix DaaS Standard is the simplest, fastest way to deliver Windows apps and desktops hosted in Microsoft® Azure. The Citrix DaaS Standard solution is managed through Citrix Cloud. The resource provisioning, capacity management, and workspace configuration are all done through the Citrix Cloud web-based tools.

The above diagram depicts the architecture for Citrix DaaS Standard. In the Citrix DaaS Standard solution, Azure subscription is managed by Citrix. Customer-managed Azure subscriptions and customer data center resources are owned and managed by the customer. The administrators have the power to provision and monitor VDAs from Citrix Cloud. End-users can access their desktops from anywhere, and any device. The above diagram is divided into four sections:

Citrix Cloud: The Citrix Cloud hosts a complete control plane for Citrix DaaS Standard. Delivery Controllers, database instances, monitoring tools, and other infrastructure components are part of Citrix DaaS Standard. Apart from Citrix DaaS Standard, other services including Citrix Gateway service, Secure Private Access, SD-WAN orchestrator, Content Collaboration, and other services are hosted on Citrix Cloud.

Citrix-Managed Azure Platform: Citrix VDAs are provisioned on this platform. Windows server and client operating systems are hosted on this platform. This platform communicates with Citrix Cloud through Citrix Cloud Connectors. A pair of Cloud Connectors is hosted within a virtual network in each resource location. End-customers do not have access to the Citrix managed Azure subscription including Cloud Connectors. Therefore, Citrix is responsible for the performance and management of the Cloud Connectors.

In case customers want to communicate with existing resources on their Azure platform, they can use a VNet peering between two virtual networks. From the Citrix Cloud, customers can configure a VNet peering to their customer-managed virtual network by giving existing Azure subscription credentials.

Customer-Managed Azure Platform: This platform is completely owned by the customer. This Azure platform is the home for multiple Azure services provisioned by the customer. These services are applied by providing high throughput connectivity to the Citrix Managed Azure platform using VNet peering. Currently, VNet peering is scoped to a single region.

Customer Data Center: The resources in the data center are completely managed by the customer. In case the organization needs to use services that are running to Citrix DaaS Standard, the customer has to establish connectivity between the Azure Platform (owned by the customer) and data center by using site-to-site VPN or SD-WAN network services.

Citrix DaaS Standard for Azure instance types

Citrix DaaS Standard uses general-purpose compute power from the Azure platform to provide different types of catalogs. A catalog is a group of identical virtual machines. Citrix DaaS Standard utilizes the D-series of VMs from Azure. The D-series VMs feature with fast CPUs and optimal CPU-to-memory configuration making them suitable for desktop workloads.

The administrator has the option to select a machine (a combination of CPU and memory) during catalog creation. Available machine types are as follows:

Multi-Session: Contains machines that are accessed by more than one user simultaneously. Supported master images are Windows 10 EVD (Multi-session) and Windows 2016 Server.

Machine type	Sessions	Virtual CPU	Memory (GB)
Light (D2s v3)	16	2	8
Medium (D2s v3)	10	2	8
Heavy (D2s v3)	4	2	8
Custom	-	2, 4, 8	4, 8, 16, 32

Static (personal desktops): This machine is a dedicated machine that has been assigned to a user during login. The desktop will only be used by that particular user. Any changes that are made to the desktop are retained at logoff.

Random (pooled desktops): This machine is a non-persistent desktop. Any changes made in the desktops are discarded after logoff. Any authenticated users can access this machine.

Machine type	Virtual CPU	Memory (GB)
B2s	2	4
D2s v3	2	8
D4s v3	4	16
D8s v3	8	32

Citrix DaaS Standard for Azure Networking

To provide users with best possible experience, Citrix DaaS Standard supports a hybrid or all-in cloud strategy using networking services. The administrators have an option to connect with their existing cloud and on-premises infrastructure and services through VNet peering only if a customer has Azure subscription present in that workload region.

To set up a connection to the corporate data center or other resources, the administrators have to make use of the Azure VNet Peering feature. This process requires Microsoft® Azure Subscription Owner privileges.

Azure VNet Peering

Virtual Network (VNet) is the fundamental building block for the private network in the Azure platform. Virtual machines can securely communicate with each other, the Internet, and on-premises networks. The Citrix Managed Azure platform is completely managed by Citrix including creating VNets, applying the policies, and so on. Customers only have visibility of the machines provisioned for them which makes Citrix DaaS Standard a pure DaaS solution.

The Citrix DaaS Standard portal gives an option to connect a customer’s existing Azure resources by configuring a VNet peering between Citrix Managed to Customer Managed Azure Virtual Networks. VNet peering is scoped to a single region.

The VNet Peering is required for VDAs in Citrix DaaS Standard to contact on-premises domain controllers, file shares, and other resources. The customer’s Azure Platform needs to have connectivity to their on-premises resources using ExpressRoute, IPsec tunnels, SD-WAN, and other site-to-site VPN technologies.

Learn more about VNet concepts, and VNet Peering by visiting the link
.

Hybrid Connectivity to on-premises resources

To enable VDAs running on Citrix DaaS Standard to communicate with on-premises resources, customers have to make a hybrid connection between a customer-managed Azure platform to their on-premises resources. Microsoft® Azure gives multiple options for hybrid connectivity. This section outlines a feasible solution for connecting an on-premises network to Azure.

VPN connection

A VPN gateway is used to send encrypted traffic between a customer’s Azure virtual network and an on-premises location over the public Internet. Each VNet can have only one VPN gateway, but administrators can create multiple connections to the same VPN gateway. In such cases, all VPN tunnels share the available gateway bandwidth.

VPN based architecture is suitable for the hybrid application if traffic between the Azure cloud and on-premises is lightweight and the customer is willing to trade latency for the processing power of the cloud.

This service is more suitable when the customer is using on-premises Active Directory services, accessing tools and services from existing virtual machines, connecting branch offices, and so on.

Azure ExpressRoute

The on-premises networks to Microsoft® Azure cloud connection are extended over a private connection provided by the service provider using Azure ExpressRoute. With this connection, the organization can utilize on-premises resources effectively for Citrix DaaS Standard. For example, it is possible to store their profiles on-premises file server, share point, or existing storage for content collaboration services, and so on.

The key benefits for deploying ExpressRoute are layer 3 connectivity between the on-premises network and Azure cloud, higher reliability, dynamic routing, and global connection to Microsoft® services across all regions.

ExpressRoute circuits are available in a wide range of bandwidth from 50 Mbps to 10 Gbps. Customers need to check with their local service provider.

Citrix SD-WAN for Citrix DaaS Standard for Azure

An organization using virtual desktops often struggles to obtain a high-quality user experience and always-on connectivity. Reliable, high-performance connectivity is even more important if the virtual desktops are used with cloud-based VOIP or video conferencing. The Citrix DaaS Standard solution offers various hybrid connectivity options to end customers with Citrix SD-WAN providing a sound choice for optimum user experience and cost-effective connectivity.

Citrix SD-WAN Architecture

Let’s review the Citrix SD-WAN architecture that helps an organization to benefit from reliable network connectivity.

The preceding diagram represents the Citrix SD-WAN architecture along with the Citrix DaaS Standard solution.

Overview of Citrix SD-WAN Architecture

Citrix SD-WAN provides the flexibility that it can be deployed in several deployment modes and to integrate the appliances, both physical and virtual, into the customer’s existing networking design and with Cloud deployments. Refer to the Citrix Tech Zone link
for the SD-WAN overview.

The solution demonstrates that the SD-WAN fits well with a customer’s existing network design and how it eases the integration process in the Azure platform for Citrix DaaS Standard. The administrator deploys a Citrix SD-WAN VPX (virtual appliance) that utilizes the internet path to establish the network connectivity from the Azure environment to a data center and branch office networks.

The Master Control Node (MCN) establishes a virtual path with Azure environment VPX using the available Internet links. This eliminates the need for establishing direct connectivity from the customer’s hosted location to Azure subscription.

Citrix recommends implementing a Citrix SD-WAN solution for Citrix DaaS Standard to improve the network connectivity and performance, required to deliver the DaaS offering and all associated applications. Also, the virtual desktop access via Citrix SD-WAN is specially optimized for Citrix HDX technologies thus providing the best user experience.

Citrix SD-WAN offers an always-on experience, changing network paths within 10 milliseconds when there’s a failure in a specific path ensuring highly available connectivity to Citrix DaaS Standard.

The preceding diagram depicts the deployment architecture of a Citrix SD-WAN solution for optimizing every connection needed to deliver a great user experience for Citrix DaaS Standard and applications. The Zscaler cloud security platform (or other SWG) is an optional component.

How Citrix SD-WAN helps in establishing connectivity to customer hosted locations

Citrix SD-WAN virtual appliances hosted on a virtual network within Azure for Citrix DaaS Standard establishes virtual network connectivity with on-premises SD-WAN appliances at office locations and, if applicable, an on-premises data center. The connectivity begins over the inexpensive internet where customers can use broadband, landline, or 4G/LTE of their choice. The Citrix SD-WAN solution is much cheaper than other hybrid connectivity options when achieving low latency and QoS features.

Citrix SD-WAN is faster and cheaper to deploy when compared to Azure ExpressRoute

• Inexpensive business internet connectivity from Azure to on-premises (Cable, DSL, 4G/LTE)

• Augment or eliminate existing expensive MPLS links

• Eliminate long timelines associated with the deployment of MPLS and ExpressRoute

• No licensing cost for Citrix SD-WAN VPX (included with Citrix DaaS Standard)

Citrix SD-WAN features can help:

• ICA connections between users and their virtual desktops and applications

• Internet access from the virtual desktops and applications to websites, SaaS apps, and other cloud resources

• Access from the Citrix DaaS Standard back to on-premises resources such as Windows Active Directory Services and database servers

• Real-Time Transport Protocol from the media engine in the Citrix Workspace app to cloud-hosted unified communications services such as Microsoft® Teams

• Client-side fetching of videos from sites like YouTube and Vimeo and filtering the access using Secure Web Gateway and third party (Zscaler, Palo Alto, Symantec, or Check Point) cloud security solution

The preceding diagram depicts a skeleton view of Citrix SD-WAN integration with Citrix DaaS Standard. The Citrix SD-WAN solution offers the easiest and best way to deliver Citrix DaaS Standard and all associated Windows, SaaS, and cloud applications. It also enables the best virtualized Microsoft® Office 365 experience.

• HDX real-time media processing performed directly on the user device for Microsoft® Teams

• Local breakout of audio-video traffic from Citrix DaaS Standard go through Azure SD-WAN VPX and then steer to nearest Microsoft® Office 365 PoP

• Unified communications and video breakout to the internet

The Key Benefits of Integrating Citrix SD-WAN with Citrix DaaS Standard for Azure

The Citrix SD-WAN solution, when used with Citrix DaaS Standard, provides various benefits compared to different hybrid connectivity solutions. A few of them are described below.

Citrix SD-WAN offers the best end-user experience

• Reliable and high-performance connectivity through advanced SD-WAN features

• Benefits across all connections (VDA-to-DC, user-to-VDA, VDA-to-cloud, user-to-cloud)

• Reduces latency compared to backhauling traffic to the data center

• Link bonding (more bandwidth for faster performance)

• High availability with seamless link failover and SD-WAN redundancy on Azure

• Optimized VoIP experience (packet racing for reduced jitter and minimal packet loss, QoS, local break-out for reduced latency)

• Traffic management: QoS across HDX traffic stream, HDX fair sharing between users and QoS between HDX and other traffic

Reference: Citrix SD-WAN integration with Citrix DaaS Standard for Azure

Citrix SD-WAN for Microsoft® Azure

Citrix SD-WAN and Azure cloud enable an organization to redesign their existing networks for optimized cloud access. Citrix SD-WAN delivers a simplified and cost-effective on-premises connection.

Citrix SD-WAN offers several benefits over Azure ExpressRoute. The primary advantage of SD-WAN is security. Many organizations prefer network architectures that integrate security, orchestration, and policy. Citrix SD-WAN covers all these factors with secured connectivity.

Benefits of Citrix SD-WAN for delivery with Citrix DaaS Standard.

• SD-WAN provides economical and highly reliable connectivity

• SD-WAN enables direct access to video-on-demand that is rendered from the customer data center

• SDWAN provides intelligent traffic steering from the VDA to other on-premises properties

• VoIP and real-time video traffic are navigated from the corporate data center

The above diagram depicts SD-WAN usage in a Citrix DaaS Standard environment using the customers Azure platform. Citrix SD-WAN provides two secure connectivity options:

• Standard-based high-speed IPsec

• Intelligent SD-WAN controller

Citrix SD-WAN is available directly from the Azure Marketplace. Customers can bring their own license and use it with a subscription or perpetual licensing options.

Citrix DaaS Standard for Azure Deployment scenarios

Citrix DaaS Standard support multiple deployment frameworks along with user authentication. In a simplified way, these are based on either the Active Directory service or Azure Active Directory Domain service usage.

Non-domain-joined catalogs

All non-domain joined catalogs feature VDAs which are not joined to a domain. In addition, the VDAs cannot have any access to an on-premises network.

Typical uses for non-domain-joined VDAs are DevOps and providing access to third-party users for code development and testing activities. In a normal workgroup, the client machine administrator does not have control over managing the users, deploy updates, and so on. But in Citrix DaaS Standard for Azure administrators have control over the machines and users the are authenticated. For user authentication there are three options:

1. Non-domain-joined catalogs with Citrix managed Azure AD

   Citrix-managed Azure AD is used to manage users. Here customers don’t must access resources from the on-premises network. This deployment is the simplest way to conduct POCs for non-domain-joined VDAs. Limited user management is performed through the Citrix DaaS Standard UI. The Citrix managed Azure AD does not offer all the options of Azure AD authentication, for example, MFA is not configurable with the Citrix managed Azure AD.

2. Non-domain-joined catalogs with customer-managed Azure AD

   For end-user authentication, a customer-managed Azure AD likely to be used. Here customers can use Azure multifactor authentication (MFA) to help safeguard access to data and applications. This method is the simplest for end-users and MFA based configuration decisions taken care of by the administrators.

3. Non-domain-joined catalogs with customer on-premises Active Directory

   End-user authentication uses a customer’s on-premises Active Directory service. Here the administrator has to install Citrix Cloud Connectors in the customer on-premises network. This method enables Citrix Workspace to access the on-premises Active Directory and authenticate users. However, the VDAs will not have any access to the on-premises network.

Domain-joined catalogs

Domain-joined catalogs feature domain-joined VDAs that have access to a customer-managed Active Directory. This Active Directory is used for user authentication.

1. Domain-joined VDAs using Azure Active Directory Domain Services (AADDS)

   In this type of deployment, the customer sets up an AADDS in their customer-managed Azure platform. They can establish a VNet peering between the Citrix-managed VNet and the customer-managed VNet so the VDAs have access to the AADDS. For end-user authentication, customers can use either Azure Active Directory that is available from their Azure Subscription, or they can use the AADDS for regular Active Directory authentication.

   The customer-managed Azure Subscription resources including AADDS are being used using VNet peering between two virtual networks within that region or location. Azure AD Domain Services is featuring all types of domain services including domain join, group policy, LDAP, Kerberos/NTLM authentication that is compatible with Windows Server Active Directory.

2. Domain Joined VDAs using customer on-premises Active Directory Domain Services

   In this type of deployment, all VDAs are domain-joined. For end-user authentication, customers can use Windows Active Directory Domain services hosted in their on-premises environment. Here Citrix DaaS Standard is running in any part of the Azure region (within Citrix DaaS Standard scope).

In case the customer is using Azure Active Directory authentication, the customer has to install Azure AD connect. The organization must run Azure AD connect on their data center which will be synced with Azure AD. Azure AD is hosted on Azure by the customer using their Azure Subscription. There will be a VNet peering required with the Citrix DaaS Standard environment. For authentication, this type of deployment uses the customer AD hosted within their data center.

Reference: Deployment scenarios

Profile Management

The user’s personal settings that are applied to the user’s virtual desktop and applications are retained using profile management. Citrix Profile Management ensures that personal settings, documents, shortcuts, templates, desktop wallpapers, cookies, and favorites always follow the user in non-persistent desktops.

The Active Directory Group Policy Objects allow the administrators to control the behavior of the Citrix user profiles. Profile Management optimizes profiles in an easy and reliable way. During the logoff and at interim stages, registry changes, files, and folders in the profile are saved to the user store for each user.

Citrix DaaS Standard offers multiple catalogs including multi-session, random-desktops supported by Windows 10 EVD and Windows 2016 servers. Customers have to create a user store in their Azure Subscription and profiles are fetched and written to the customer’s file share. The administrators have to make sure there is reliable network connectivity between Citrix DaaS Standard (multi-session and random catalog) and the file servers storing the user profiles.

The user store is the central network location for storing Citrix user profiles. File servers are created in customer’s Azure Subscription with Availability set. For a user store, any SMB or CIFS files share that can be used. Make sure that the shared path is accessible by the accounts used with Citrix user profiles.

Profiles are loaded to any non-persistent desktops from that shared path over the network. VNet peering uses Azure backbone which provides low latency and robust network. VNet peering supported within the region, so this option is scoped singled region or location.

Reference: Profile Management

Profile Management using FSLogix profile container with Azure Files

Most organizations integrate some form of a profile management solution. As a result of the profile solution, end-users can sometimes face challenges in accessing their profile over the network due to the profile management being unable to handle large files and modern settings.

To overcome these problems Microsoft® introduced the FSLogix container solution for profile and office 365. FSLogix provides the best performing end-user computing environment, reduces management costs, simplifies the computing infrastructure.

FSLogix Profile Containers

In Citrix DaaS Standard, multi-session and random desktop catalogs will have user profiles that are not retained after logoff. FSLogix is designed to roam profiles in a Citrix DaaS Standard environment. This solution is accomplished by allowing the complete user profile to be stored in a single container.

During logon, the container is dynamically attached to the machine (VDA) that is running on the Citrix Managed Azure Subscription using VHD or VHDX Microsoft® services. These profiles are available to the user’s system as a native-like user profile. The large files are elegantly handled by the FSLogix Profile Containers solution to help ensure optimal user experience.

Office 365 Containers

Users demand productive experience with Microsoft® Office including fast email, fast searching, fast access to OneDrive files, and so on. The data and search indexes are stored in the container vs the whole user profile.

This solution easy to integrate over any existing profile management solution. In case using a profile management solution and office container, it is recommended to exclude the portion of the profile managed by Office 365 container.

Azure Files

As previously stated, the user profile is stored as a container and this container is dynamically attached to the VDAs during logon. Supported by VHD or VHDX the user profile containers are immediately available and appear after user login. Containers or disks stored in the cloud that are accessible via SMB protocol. Azure Files offers complete management of file shares hosted in the customer-managed Azure Subscription.

Azure Files are easily managed through the Azure portal, providing greater resiliency (LRS, ZRS). In terms of scalability, it can grow to 100 TB with multiple partitions. There are also advantages of performance factors given that Azure files provide 10,000 to 100,000 IOPS.

The administrator has to create Azure Files for storing profiles in customer-managed Azure subscription. The above picture shows Citrix Managed VDAs are fetching the profiles from Azure Files over the network. The customer has to set up the VNet peering between the subscriptions.

FSLogix profile container binaries have to be installed on the base image during the master image preparation. Once all the tools and applications are installed, the VM has to be shut down. When the user logs in to a non-persistent VDA (newly created) a profile is created on the file share. Any changes made in that desktop will be stored on that particular container.

Learn more about the FSLogix Profile container solution, at this link
.

Reference: FSLogix

Monitoring of Citrix DaaS Standard for Azure

The Citrix DaaS Standard Monitor dashboard gives the details of desktop usage, sessions, and machines in the deployment. The administrators can also control sessions, power-managed machines, end-user running applications, and end-user running processes.

Monitor provides:

• Real-time data from the Citrix DaaS Standard services running in the background

• Historical data stored in the Monitor database to access the usage report

• Visibility of machines running on Citrix Managed Azure subscription

• Controlling capability for applications running on the VDA

• Also provides session control capability with power management options

The Managed Desktop usage page appears when the administrator selects the Monitor tab. Here it gives complete information about all catalogs. It also gives graphs with the number of powered-on machines and peaks concurrent sessions at regular points during the time period selected.

Controlling user’s applications and sessions

From the Monitor dashboard, administrators can apply filters to log off or disconnect a session. This option can be found by searching for a user.

Power-control machines

Single session or multi-session machines are displayed by applying the filtered search. By clicking Power Control action on the portal the administrator gets an option to restart, force restart, shutdown, force shutdown, and start the machines running on the Citrix DaaS Standard environment.

Reference: Monitor

User Access and Authentication

Citrix Workspace app is the entry point to access desktops and apps running on the Citrix DaaS Standard platform. The user has to first be authenticated when they log in to Citrix Workspace. Citrix DaaS Standard supports the following user authentication methods:

• Citrix Managed Azure AD (AAD)

• Customer’s choice of Identity provider

Citrix Managed Azure AD: Azure Active Directory service is provided and managed by Citrix. Here the administrator does not need to provide or own any Azure infrastructure. Citrix has made it simple to manage, the admins have to add their users to the directory using the Citrix DaaS Standard UI.

Customer’s choice of Identity provider: In this authentication method, customers can use any available authentication method in Citrix Cloud. Including customer managed Azure Active Directory, Okta and SAML 2.0 based authentication mechanisms.

One option is to synchronize user identities between cloud and local directories so that Citrix DaaS Standard users can access their resources from Citrix Cloud. Using a single set of credentials users are able to access their Citrix DaaS Standard resources through Citrix Workspace App. To achieve this, customers have to install and configure Azure AD Connect on their on-premises.

Azure AD Connect sync takes care of all the operation that is related to synchronize identity data between the on-premises environment and Azure AD.

Another option is to use customer-managed Azure AD with a non-domain joined catalog. In this scenario, the customer-managed Azure AD would be entirely in the cloud with no on-premises connection or synchronization. This method is ideal for customers who do not have any legacy Active Directory or on-premises infrastructure.

Reference: User Authentication

Connect Citrix Cloud to Azure AD

To connect the existing Azure Active Directory with Citrix Cloud, the administrator must have Global Admin privileges in the Azure AD. Citrix Cloud needs permission to access the user profile in addition to the basic profiles of the users in the Azure AD. The administrator has to select the “Identity and Access Management” from Citrix Cloud. Fill in all the required details and sign in to the Azure account to connect. Then Citrix Cloud accesses the account and acquires the information required for connection.

After the Azure AD user accounts are connected, users can sign in to Citrix Cloud using a URL that is configured during the initial connection or by selecting “Sign in with my company credentials”.

Reference: AAD to Citrix Cloud

Advanced multifactor authentication is provided by Azure AD. Turn-on the available features on the customer Azure AD, which enables Citrix Cloud users to use those capabilities by default.

Image Management

Image Management is the process of creating a master or golden image that contains the operating systems and all the required applications. A single image is delivered to multiple target virtual machines by the image provisioning mechanism. The Citrix DaaS Standard solution uses Citrix proven Machine Creation Service (MCS) technology to provision virtual machines on the Citrix Managed Azure Subscription.

Machine Creation Services configures, starts, stops, and deletes virtual machines using Microsoft® Azure APIs. MCS is a disk-based provisioning approach that integrates well within the Microsoft® Azure cloud platform. Citrix DaaS Standard provides several Citrix-managed master images:

• Windows 10 Enterprise (single session)

• Windows 10 EVD and Windows Server 2016 (multi-session)

Citrix DaaS Standard supports both server and desktops OS environments. Citrix administrators can create three types of machine catalogs using Citrix Machine Creation Services. Machine types are:

• Multi-session - Windows 10 EVD (Multi-session) or Windows Server 2016 with latest VDA

• Static (personal desktops) - Windows 10 Pro with latest VDA

• Random (pooled desktops) - Windows 10 Pro with latest VDA

Citrix offers customers an option to build their own image by using existing master images. These master images are used by the administrator to create a virtual machine to build their customized image for Citrix DaaS Standard.

Import a master image from Azure

In the case customer has their customized images available in their Azure Subscription, images are directly imported to Citrix DaaS Standard. The administrator has to enter the Azure-generated URL for the Virtual Hard Disk (VHD).

Citrix runs the validation test on the imported image. The administrator has to make sure the image has all the requirements to run on Citrix DaaS Standard. The requirement is:

• Operating system support (Windows 10 Enterprise, Windows 10 Enterprise Virtual Desktop preview, or Windows Server 2016)

• No configured Delivery Controllers

• Valid Citrix VDA newer than 7.11 installed and matching the operating system (for example server VDA on server OS)

• The personality.ini file must exist on the system drive (VDA is set to MCS provisioning)

Note: Before importing a master image from Azure, administrator makes sure that the Azure Virtual Machine Agent is installed on the image.

Learn more about importing a master image from Azure and installation of VDA on the master image, at this link
.

To create and managed master images refer to product documentation
.

Optimization of the image

The image may contain multiple unused services that used to create the machine catalog on Citrix DaaS Standard. OS optimization helps to remove or disable unwanted services running on an image. Citrix has developed an optimization tool called “Citrix Optimizer.” This tool helps Citrix administrators to optimize various components in an environment. The tool is PowerShell based and also includes a graphical UI.

Citrix Optimizer runs in three different modes:

• Analyze - analyze the current system against a specified template and display any differences

• Execute - apply the optimization from the template

• Rollback - revert the optimization changes applied previously

The administrator has to choose the relevant template from the selection for OS optimization. Also, the administrator has an option to select and disable unwanted services from the image. By disabling such services master image becomes easier to use on the Azure cloud platform. This tool helps in optimizing resource consumptions and overall performance.

Learn more about the installation and updates of Citrix Optimizer CTX224676
.

Licensing and Azure Subscription

Licensing for Citrix DaaS Standard handled by Citrix. The administrator has privileges to set up a Microsoft® RDS license server for Windows Server workloads.

The multi-session catalog requires a Remote Desktop Services client access license (RDS CAL). The Remote Desktop Services license server issues client access licenses to devices and users. The administrator can activate the license server by using the Remote Desktop Licensing Manager.

Activate the license server in any one of the available machines through Remote Desktop Licensing Manager. The VM must always be available and Citrix VDAs must be able to reach this license server. Specify the license server address and per-user license mode using Microsoft® Group Policy. The Remote Desktop licensing mode configured on the remote desktop server must match the type of RDS CALs available on the license server.

Azure Subscription

Citrix Managed Azure Subscription: This subscription is completely owned by Citrix, where the end user’s desktop is running on this platform.

Customer Managed Azure Subscription: This subscription owned by a customer running their own licensed workloads on Microsoft® Azure platform has to go through the Azure Hybrid Benefit.

Bring-Your-Own Azure Subscription

The Citrix DaaS Standard solution allows customers to use Citrix’s Azure subscription or a customer’s Azure subscription. Customers can bring their own Azure subscription which in turn allows any existing Microsoft® Azure customer to easily adopt Citrix DaaS Standard as part of their overall Azure cloud strategy.

To enable BYO Azure flexibility, a customer must add one or more existing Azure subscriptions to Citrix DaaS Standard. This action authorizes Citrix DaaS Standard to access customer subscriptions.

There are a few limitations on the BYO Azure subscription model that are described below:

• Supports only domain-joined catalogs

• Customers can only get a “custom to create” catalogs option

• Customer must create a new virtual network or have the option to select the existing one

With the BYO Azure subscription model, the customer has full control over the VDAs running on their subscription. Also, image management becomes easier in terms of importing the image and managing the existing images.

Reference: Bring-your-own Azure Subscription

Windows 10 EVD licensing

Azure Virtual Desktops (AVD) also known as Windows 10 Enterprise Virtual Desktops service and capabilities are extended and enriched by Citrix DaaS Standard through Citrix Cloud. This progression of remote desktop service available only on the Microsoft® Azure platform.

To deploy and manage a multi-session catalog using Azure Virtual Desktops customer gets a Windows 10 Enterprise E3 entitlement. A new Windows 10 EVD operating system licensed as part of Azure Virtual Desktops in Azure.

Extra benefits of Azure Virtual Desktop are customer gets Windows 7 virtual desktop with free Extended Security Updates. AVD offers flexible service allowing administrators to virtualize both desktops and apps.

Best Practices and Design Considerations for Citrix DaaS Standard for Azure

While adopting the Citrix DaaS Standard service for an organization, solution architects and administrators have to consider best practices and design considerations. It is important to align these with business needs.

The Citrix DaaS Standard service components computing, storage, and networking (in Citrix managed Azure subscription) are all managed by Citrix. The architects do not need to worry about the infrastructure side unless on-premises connectivity is required. There are a few important points to considered though:

• Conducting a pre-assessment before moving to Citrix DaaS Standard

• Deployment considerations and image optimization

• Power Management

• Security

• Applying patches and antivirus software

• Multifactor authentication

• Profile Management

Conducting a pre-assessment before moving to Citrix DaaS Standard for Azure

To gain an understanding of the workloads, the solution architect has to do pre-assessment of the desktops and applications that run in the Citrix DaaS Standard environment. It is critically imperative to design and gather resource requirement data for Citrix DaaS Standard.

Pre-assessment is useful to determine the specific applications required for the users, the licensing requirement, and calculate the cost associated with the deployment. Citrix provides the Citrix DaaS Standard cost calculator to understand cost estimation for the deployment. Actual prices may vary depending upon other factors including date of purchase, type of agreement with Citrix, and so on.

Calculate your total DaaS costs with the Citrix DaaS Standard for Azure Cost Calculator
.

Deployment considerations and image optimization

Many organizations confront the challenge of effectively scaling resources to meet demand. In case merger and acquisition take place then the organization faces challenges when the data center is under-resourced. Citrix DaaS Standard makes it possible to mitigate the scalability constraints. Customers can provision compute on an availability region nearest to their data center situated with reliable connectivity.

All the end-users use Citrix Workspace app to access their resources and that is the only single-point of entry. In case customers are using a file server or any other services running on their Azure Subscription, it is the customer’s responsibility to implement VNet peering between subscriptions. At the back-end, the Azure backbone network with a bandwidth of 25 Gbps used to link between subscriptions.

There is a cost associated with CPU, memory, and bandwidth consumption so customers have to plan their deployment depending on the need.

Image Optimization is an important task where administrators have to perform on the master image. Disable all the unwanted services and remove the application which is not used by users. This optimization reduces fewer CPU cycles and memory consumption.

Power Management

Power management options are available for catalogs containing multi-session and single-session machines. This task helps in minimizing the cost associated with resource consumption on the Citrix Managed Azure platform.

The administrator has an option to set the working hours depending on the time zone. In some of the use cases, machines do not need to be powered-on after working hours. In such scenarios, power management is a viable option for administrators to power-off those machines. Here administrators can set the start and stop time. Perhaps there are other options available as well that are tuned by administrators to get the best balance of price to responsiveness:

• Disconnect idle sessions: Idle desktops are disconnected, and the user has to log in to Workspace to start the machine

• Log off disconnected session: The administrator can set the time to log off disconnected sessions. Users experience longer logon times and lose any unsaved work, but the machine can power off if there are no logged-in sessions

• Power-off delay: Set the time for a machine to be powered-on before it is eligible for power-off

• Capacity buffer option: Gives the option to meet a sudden spike in demand by keeping a buffer of machines powered-on. This step has to be entered in percentage, a lower value decreases the cost while higher value ensures optimal user experience (no wait time)

To create a power management schedule, refer to the reference section.

Reference: Power Management
.

Security

Secure virtual desktops significantly mitigate risks to a company by being within the protected network. Network-level isolation secures the Citrix DaaS Standard from external threats. Only outbound connectivity to the Internet is enabled by default in virtual machines. To access these machines Citrix Workspace app is the single entry point for end-users. The administrators can use the support and troubleshoot option for machines that are domain-joined. Citrix prepared images to have Windows Defender Antivirus enabled by default. The customer has the option to make their images more secure during the master image preparation by installing different antivirus software. There are other considering factors an administrator need to take into the account when considering security:

• Applying patches and antivirus software: During the master image creation, it is best practice to apply relevant patches. This process makes the environment safe from malicious users that exploit vulnerabilities left open when operating systems are not kept up-to-date

• Multifactor authentication: This layer of security in the form of multifactor authentication protects critical corporate resources accessed via Citrix DaaS Standard solutions. Most of the data breaches arising from credentials compromised by enabling MFA it mitigates the risk

Azure multifactor authentication helps safeguard access to Citrix DaaS Standard. With Conditional Access, the administrator can implement automated access control for accessing Citrix DaaS Standard based on conditions. To learn more about Azure MFA follow the Microsoft® documentation.

For more information on security refer to the technical security overview documentation.

Reference: Technical security overview

Profile Management

Profile management ensures that the user’s personal settings are retained for non-persistent desktops. Profile management gives reliable roaming experience to users. The end-user personal settings, documents, shortcuts, templates, desktop wallpapers, cookies, and favorites always follow the user across different Windows machines on any device. Before implementing Profile Management on the environment few factors to be considered. This includes the type of catalog, understanding the application behavior, pilot test on a few users then going for all users, and network share to store all the profiles.

For a detailed explanation of deciding factors, refer the Profile management
documentation from Citrix.

For the user share to store the profile, it is recommended to create a Windows file share on customers Azure subscription and all the user profiles are stored in that particular share. During the login, the profile is fetched over the network using Azure backbone network. This reduces the latency and faster logon times to the machines.

Sources

Goal of this reference architecture is to assist you with planning your own implementation. To make this job easier, we would like to provide you with source diagrams that you can adapt in your own detailed designs and implementation guides: source diagrams
.

References

The following resources are referenced for a better understanding of Citrix DaaS Standard for Azure:

Citrix DaaS Standard for Azure

Citrix DaaS Standard Architecture