Parallels RAS provides vendor independent virtual desktop and application delivery from a single platform. Accessible from anywhere with platform-specific clients and web enabled solutions, like the built-in Parallels Web Client, Parallels RAS allows you to publish remote desktops, applications and documents, improving desktop manageability, security and performance.
Parallels RAS extends Windows Remote Desktop Services by using a customized shell and virtual channel extensions over the Microsoft RDP protocol. Parallels RAS supports all major hypervisors from Microsoft, VMware, and other vendors including Hyperconverged solutions such as Nutanix AHV (AOS) and Scale Computing and Cloud platforms and services such as Microsoft Azure and Azure Virtual Desktop (formerly known as Windows Virtual Desktop), enabling the publishing of virtual desktops and applications to Parallels Client.
The product includes powerful universal printing and scanning functionality, as well as resource-based load balancing and management features.
With Parallels Device Manager Module for Parallels RAS you can also centrally manage user connections and PCs converted into thin clients using the free Parallels Client.
When a user requests an application or a desktop, Parallels RAS finds a least loaded RD Session Host or a guest VM on one of the least loaded Providers and establishes an RDP connection with it. Using Microsoft RDP protocol, the requested application or desktop is presented to the user. Note that in addition to RD Sessions Hosts and VDI, Parallels RAS can also be used to configure, manage and publish Azure Virtual Desktop resources.
Users can connect to Parallels RAS using Parallels Client (available at no charge), which can run on Windows, Linux, macOS, Android, Chrome, iOS and iPadOS. Users can also connect via an HTML5 browser or Chromebook.
As newer versions of Windows keep on being developed as time goes by, you need to defend the migration cost to your business. Parallels RAS can help. Desktop replacement allows you to extend the lifespan of your hardware and delay migration to the latest OSs to a time that suits you best. The Parallels RAS solution allows you to be very flexible: you can lock machine configurations on the user side, placing your corporate data in an extremely secure position; or you can opt to allow users to run some local and remote applications. Parallels Client Desktop Replacement is able to reduce the operability of the local machine by disabling the most common local configuration options, while guaranteeing the same level of service and security afforded by thin clients, directly from your existing PCs.
This guide is intended for system administrators responsible for installing, configuring, and administering Parallels RAS. This guide assumes that the reader is familiar with Microsoft Remote Desktop Services and has an intermediate networking knowledge.
Term/Abbreviation
Description
RAS Console
Parallels RAS Console.
The RAS console is the primary interface you use to configure, manage, and run Parallels RAS. As an administrator, you use the RAS console to manage Farms, Sites, RD Session Hosts, published resources, client connections, etc.
Category
In the RAS console, categories are displayed in the left pane of the main window. Each category consists of a number of settings related to a specific task or operation.
The categories include Start, Farm, Load Balancing, Publishing, Universal Printing, Universal Scanning, Connection, Device Manager, and others.
Farm
A Parallels RAS Farm is a logical grouping of objects for the purpose of centralized management. A Farm configuration is stored in a single database which contains information about all objects comprising the Farm. A Farm consists of at least one Site but may have as many sites as necessary (see Site below).
Site
A Site consists of at least one RAS Connection Broker, RAS Secure Gateway (or multiple gateways), and RAS agents installed on RD Session Hosts, Providers, and Windows PCs. Note that a given RD Session Host, Provider, or PC can be a member of only one Site at any given time.
Licensing Site
The Site that manages Parallels RAS licenses in a Parallels RAS Farm. By default, the server on which you install Parallels RAS becomes the Licensing Site. If you create additional sites later, you can designate any one of them as the Licensing Site.
There can be only one Licensing Site in a given Farm. All other sites are called secondary sites.
Note: Parallels RAS updates or upgrades must be applied to the Licensing Site first.
RAS Secure Gateway
RAS Secure Gateway tunnels all traffic needed by applications on a single port and provides secure connections.
Web Client
Web Client allows users to view and launch remote applications and desktops in a web browser. The Web Client functionality is a part of RAS Secure Gateway.
Publishing
The act of making items installed on a Remote Desktop Server, Provider or Remote PC available to the users via Parallels RAS.
RAS Connection Broker
RAS Connection Broker provides load balancing of published applications and desktops.
RAS RD Session Host Agent
RAS RD Session Host Agent collects information from Microsoft RDS hosts required by the Connection Broker and transmits to it when required.
Remote PC Agent
Remote PC Agent collects information from Remote PC hosts required by the Connection Broker and transmits to it when required.
RAS Guest Agent
RAS Guest Agent collects information from the VDI desktop required by RAS Connection Broker and transmits to it when required.
RAS Provider Agent
RAS Provider Agent collects information from the Parallels RAS Infrastructure and is responsible for controlling VDI through its native API. RAS Provider Agent is built into the RAS Connection Broker and is available by default. It can be used to control multiple Providers in a Parallels RAS Farm.
RAS Provider Agent dedicated
RAS Provider Agent dedicated is similar to the RAS Provider Agent described above with one important difference — it is a separate component that must be installed from the Parallels RAS installer and can only control a single Provider.
RDSH or RD Session Host
RDSH makes applications and a full desktop accessible to a remote client that supports Remote Desktop Protocol (RDP). RDSH replaced Terminal Servicer beginning with Windows 2008 R2.
HALB
High Availability Load Balancing (HALB) is an appliance that provides load balancing for RAS Secure Gateways. Parallels HALB virtual appliance is available for the following hypervisors: Hyper-V, VMware. Multiple HALB Virtual Servers representing different HALB devices can be deployed in a single Site. Multiple HALB deployments can run simultaneously, one acting as the primary and others as secondaries. The more HALB deployments a Site has, the lower the probability that end users will experience downtime. Primary and secondary HALB deployments share a common or virtual IP address (VIP). Should the primary HALB deployment fail, a secondary is promoted to primary and takes its place.
Tenant Broker
Tenant Broker is a special RAS installation that hosts shared RAS Secure Gateways. It is an essential part of the RAS multi-tenant architecture.
Tenant
Tenants are RAS farms that join Tenant Broker (see above) and use shared RAS Secure Gateways and HALB thus eliminating the need to have their own Gateways and HALB deployed.
RAS Enrollment Server
RAS Enrollment Server is an essential component of the SAML SSO Authentication functionality. It communicates with Microsoft Certificate Authority (CA) to request, enroll, and manage digital certificates on behalf of the user for SSO authentication in the Parallels RAS environment.
RAS PowerShell
Parallels RAS PowerShell allows you to perform Parallels RAS administrative tasks using PowerShell cmdlets. You can execute cmdlets in the Windows PowerShell console or you can write scripts to perform common Parallels RAS administrative tasks. A complete guide to Parallels RAS PowerShell is available on the Parallels website together with other Parallels RAS documentation.
RAS REST API
Parallels RAS comes with various APIs to help you develop custom applications that integrate with it. The RAS REST API is one of them.
RAS Management Portal
Parallels RAS Management Portal is an HTML5 browser-based application that lets you manage Parallels RAS.
RAS Web Administration Service
A Web service that provides the user interface for RAS Management Portal and implements RESTful Web services for the RAS REST API (see above).
Azure Virtual Desktop
Azure Virtual Desktop is a desktop and app virtualization service running on Microsoft Azure, providing access to RD Session Hosts and VDI. Parallels RAS 18 provides the ability to integrate, configure, maintain, support and access Azure Virtual Desktop workloads on top of the existing technical capabilities of Parallels RAS.
FSLogix
FSLogix Profile Container is a remote profile solution for non-persistent environments. Parallels RAS supports FSLogix on RD Session Hosts, VDI, and Azure Virtual Desktop.
Welcome to Parallels® Remote Application Server (Parallels RAS), an integrated solution to virtualize your applications, desktops and data. Parallels RAS publishes applications and delivers remote and virtual desktops to any device on your network, anywhere.
The following table lists the Parallels RAS 20 release history. Parallels RAS documentation is updated for every release. This guide refers to the latest Parallels RAS release from the table below. If you are using a newer Parallels RAS release or version, please download the current version of the guide from https://www.parallels.com/products/ras/resources/.
20.0
Major release
10/30/2024
20.0
Hotfix 1
11/25/2024
20.1
Release
12/12/2024
20.1
Hotfix 1
12/20/2024
20.2
Release
03/04/2025
20.2
Hotfix 1
03/27/2025
20.2
Hotfix 2
04/14/2025
20.2
Update 1
06/19/2025
The following new features were added in Parallels RAS 20.2:
Deprecations and updated system requirements:
See for updated system requirements for components and clients.
The following new features were added in Parallels RAS 20.1:
Support for Nutanix AOS 6.10
The following new features were added in Parallels RAS 20:
AWS Availability Zones support for and host pools
Added support for SC//HyperCore 9.4
Added support for the Swiss and Belgian keyboard layouts in the policies
The following new features were added in Parallels RAS 19.4.2:
.
.
The following new features were added in Parallels RAS 19.4.1:
The following new features were added in Parallels RAS 19.4:
Ability to automatically upgrade Agents on , , and .
Support for IGEL 11 and 12.
Extended image management for Nutanix AHV (AOS).
The following new features were added in Parallels RAS 19.3.1:
Azure Virtual Desktop improvements.
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.3:
Template versioning for RD Session Hosts, VDI, and Azure Virtual Desktop. This feature includes the following:
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.2.f3:
.
.
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.2.2:
A. You can also .
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.2:
.
Disk storage cost optimization for and .
Ability to choose the transport protocol for connections between Parallels Client and a server on , , and .
Deprecations and updated system requirements:
See for updated system requirements for components and clients.
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.1:
.
.
.
.
Deprecations and updated system requirements:
See for updated system requirements for components and clients.
For the complete list of new features and improvements, see Release notes: .
The following new features were added in Parallels RAS 19.0:
.
.
.
New Parallels Client for Windows for ARM64.
Deprecations and updated system requirements:
See for updated system requirements for components and clients.
For the complete list of new features and improvements, see Release notes: .
Ability to select whether unenrolled users can see the The user name or password is incorrect error when they enter incorrect credentials for TOTP, Google Authenticator, and email OTP.
Support for Scale Computing SC//HyperCore 9.2.
Validation of HTTP host headers to protect against host header injections.
Sessions disconnections for host pools
Transport protocol for host pools
Bandwidth availability for host pools
Latency for host pool
Connection quality for host pool
UX Evaluator for host pool
Logon duration for host pool
Azure Virtual Desktop improvements.
Scheduled template recreation for RD Session Hosts, VDI, and Azure Virtual Desktop.
Ability to configure user profiles and other settings on the host pool level.
Dynamic printer mapping.
Azure Virtual Desktop improvements.
Add multiple provider addresses for the SC//HyperCore provider.
Ability to hide billing information on Tenants.
Ability to recreate hosts keeping the existing MAC addresses on the SC//HyperCore provider.
TLS 1.3 support.
Terminology updates:
References to Pools/Groups have been standardized as "Host Pools".
Reference to Desktop/Guests have been standardized as "Hosts".
Session activity
Disconnection reasons
New policy for selecting the display configuration.
Ability to recreate RD Session Hosts and hosts with their original BIOS UUID on ESXi and vCenter (works automatically).
Transport protocol (TCP/UDP)
Network latency
Connection quality
Bandwidth availability
Expression-based client policies, filtering for published resources and MFA configuration.
Power management: starting up and shutting down servers on schedule. Schedules can be created for RD Session Hosts, VDI, and AVD hosts.