Product Documentation

Connect user devices and published resources

Aug 17, 2016

You can optimize the connection of your user devices to resources published in the server farm:

  • Provide continuity for roaming users
  • Make scanning transparent for users
  • Map client devices

Providing continuity for roaming users

Workspace control lets desktops and applications follow users as they move between devices. This enables, for example, clinicians in hospitals to move from workstation to workstation without having to restart their desktops and applications on each device.

Policies and client drive mappings change appropriately when you move to a new user device. Policies and mappings are applied according to the user device where you are currently logged on to the session. For example, if a health care worker logs off from a user device in the emergency room of a hospital and then logs on to a workstation in the hospital’s X-ray laboratory, the policies, printer mappings, and client drive mappings appropriate for the session in the X-ray laboratory go into effect for the session as soon as the user logs on to the user device in the X-ray laboratory.

Workspace control is available only to users connecting to published resources with Citrix XenApp or through StoreFront, Receiver for Web, or the Web Interface.

Making scanning transparent for users

If you enable HDX Plug-n-Play TWAIN image scanning device support, users can control client-attached TWAIN imaging devices transparently with applications that reside on the server farm. To use this feature, a TWAIN device must be attached to the user device and the associated 32-bit TWAIN driver must also be installed on the user device.

To enable or disable this feature, configure the Citrix policy Client TWAIN device redirection setting.

The following policy settings allow you to specify the maximum amount of bandwidth (in kilobits per second or as a percentage) and the compression level of images from client to server used for TWAIN redirection:

  • TWAIN device redirection bandwidth limit
  • TWAIN device redirection bandwidth limit percent
  • TWAIN compression level

Map client devices

Receiver supports device mapping on user devices so they are available from within a session. Users can:

  • Transparently access local drives, printers, and COM ports
  • Cut and paste between the session and the local Windows clipboard
  • Hear audio (system sounds and .wav files) played from the session

During logon, Receiver informs the server of the available client drives, COM ports, and LPT ports. By default, client drives are mapped to server drive letters and server print queues are created for client printers so they appear to be directly connected to the session. These mappings are available only for the current user during the current session. They are deleted when the user logs off and recreated the next time the user logs on.

You can use the redirection policy settings to map user devices not automatically mapped at logon. For more information, see the XenDesktop or XenApp documentation.

Turn off user device mappings

You can configure user device mapping including options for drives, printers, and ports, using the Windows Server Manager tool. For more information about the available options, see your Remote Desktop Services documentation.

Redirect client folders

Client folder redirection changes the way client-side files are accessible on the host-side session. When you enable only client drive mapping on the server, client-side full volumes are automatically mapped to the sessions as Universal Naming Convention (UNC) links. When you enable client folder redirection on the server and the user configures it on the user device, the portion of the local volume specified by the user is redirected.

Only the user-specified folders appear as UNC links inside sessions instead of the complete file system on the user device. If you disable UNC links through the registry, client folders appear as mapped drives inside the session. For more information, including how to configure client folder redirection for user devices, see the XenDesktop 7 documentation.

Map client drives to host-side drive letters

Client drive mapping allows drive letters on the host-side to be redirected to drives that exist on the user device. For example, drive H in a Citrix user session can be mapped to drive C of the user device running Receiver.

Client drive mapping is built into the standard Citrix device redirection facilities transparently. To File Manager, Windows Explorer, and your applications, these mappings appear like any other network mappings.

The server hosting virtual desktops and applications can be configured during installation to map client drives automatically to a given set of drive letters. The default installation maps drive letters assigned to client drives starting with V and works backward, assigning a drive letter to each fixed drive and CD-ROM drive. (Floppy drives are assigned their existing drive letters.) This method yields the following drive mappings in a session:

Client drive letter Is accessed by the server as:
A A
B B
C V
D U

The server can be configured so that the server drive letters do not conflict with the client drive letters; in this case the server drive letters are changed to higher drive letters. For example, changing server drives C to M and D to N allows client devices to access their C and D drives directly. This method yields the following drive mappings in a session:

Client drive letter Is accessed by the server as:
A A
B B
C C
D D

The drive letter used to replace the server drive C is defined during Setup. All other fixed drive and CD-ROM drive letters are replaced with sequential drive letters (for example; C > M, D > N, E > O). These drive letters must not conflict with any existing network drive mappings. If a network drive is mapped to the same drive letter as a server drive letter, the network drive mapping is not valid.

When a user device connects to a server, client mappings are reestablished unless automatic client device mapping is disabled. Client drive mapping is enabled by default. To change the settings, use the Remote Desktop Services (Terminal Services) Configuration tool. You can also use policies to give you more control over how client device mapping is applied. For more information about policies, see the XenDesktop or XenApp documentation in eDocs.

HDX Plug-n-Play for USB Storage Devices

HDX Plug-n-Play for USB storage devices enables users to interact with USB mass storage devices connected to their user devices when connected to XenApp sessions. When HDX Plug-n-Play for USB storage devices is enabled, users can connect or disconnect a USB device from a session at any time, regardless of whether the session was started before or after the drive connection.

HDX Plug-n-Play for USB storage devices is enabled by default and can be disabled or enabled by editing the ICA\File Redirection - Client removable drives policy setting. For more information, see the XenApp documentation.

Supported Mass Storage Devices with XenApp

Mass storage devices, including USB thumbdrives, USB-attached hard drives, CD-DVD drives, and SD card readers are supported.

Not supported:

  • U3 smart drives and devices with similar autorun behavior
  • Explorer.exe published as a seamless application

Mass storage devices can often be accessed through client drive mapping, and so USB support is not required.

Important: Some viruses are known to propagate actively using all types of mass storage. Carefully consider whether or not there is a business need to permit the use of mass storage devices, either through client drive mapping or USB support.

HDX Plug and Play USB device redirection

HDX Plug and Play USB device redirection enables dynamic redirection of media devices, including cameras, scanners, media players, and point of sale (POS) devices to the server. You or the user can restrict redirection of all or some of the devices. Edit policies on the server or apply group policies on the user device to configure the redirection settings. For more information, see the XenDesktop or XenApp documentation in eDocs.

Important: If you prohibit Plug and Play USB device redirection in a server policy, the user cannot override that policy setting.

A user can set permissions in Receiver to always allow or reject device redirection or to be prompted each time a device is connected. The setting affects only devices plugged in after the user changes the setting.

Mapping client printers for more efficiency

The Receiver support printing to network printers and printers that are attached locally to user devices. By default, unless you create policies to change this, XenApp lets users:

  • Print to all printing devices accessible from the user device
  • Add printers (but it does not retain settings configured for these printers or save them for the next session)

However, these settings might not be the optimum in all environments. For example, the default setting that allows users to print to all printers accessible from the user device is the easiest to administer initially, but might create slower logon times in some environments.

Likewise, your organization’s security policies might require that you prevent users from mapping local printing ports. To do so, configure the Citrix policy Auto connect client COM ports setting to Disabled.

To change default printing settings, configure policy settings on the server. For more information, see the XenApp administration topics.

View mapped client printers

While connected to the XenApp server, from the Start menu, choose Printers in the Control Panel.

The Printers window displays the local printers mapped to the session. When connecting to servers running Citrix Presentation Server 4.0 or 4.5 or Citrix XenApp, by default the name of the printer takes the form:

printername (from clientname) in session x

where:

  • printername is the name of the printer on the user device.
  • clientname is the unique name given to the user device or the Web Interface.
  • x is the SessionID of the user’s session on the server.

For example, printer01 (from computer01) in session 7

When connecting to servers running Presentation Server 3.0 or earlier, or when the Legacy printer name option from the Citrix policy Client printer names setting is enabled on the server, a different naming convention is used. The name of the printer takes the form:

Client/clientname#/printername

where:

  • clientname is the unique name given to the user device during client setup.
  • printername is the Windows printer name. Because the Windows printer name is used and not the port name, multiple printers can share a printer port without conflict.

For more information about printing, and about managing printing using policies, see the Citrix XenApp Administrator's documentation.

Map a client COM port to a server COM port

Client COM port mapping allows devices attached to the COM ports of the user device to be used during sessions. These mappings can be used like any other network mappings.

You can map client COM ports at the command prompt. You can also control client COM port mapping from the Remote Desktop (Terminal Services) Configuration tool or using policies. For information about policies, see the XenDesktop or XenApp documentation.

  1. For XenDesktop 7 deployments, enable the Client COM port redirection policy setting.
  2. Log on to Receiver.
  3. At a command prompt, type: net use com x: \\client\z:

    where x is the number of the COM port on the server (ports 1 through 9 are available for mapping) and z is the number of the client COM port you want to map.

  4. To confirm the operation, type: net use

    at a command prompt. The list that appears contains mapped drives, LPT ports, and mapped COM ports.

    To use this COM port in a virtual desktop or application, install your user device to the mapped name. For example, if you map COM1 on the client to COM5 on the server, install your COM port device on COM5 during the session. Use this mapped COM port as you would a COM port on the user device.

    Important: COM port mapping is not TAPI-compatible. TAPI devices cannot be mapped to client COM ports.

Mapping Client Audio to Play Sound on the User Device

Client audio mapping enables applications executing on the XenApp server to play sounds through Windows-compatible sound devices installed on the user device. You can set audio quality on a per-connection basis on the XenApp server and users can set it on their device. If the user device and server audio quality settings are different, the lower setting is used.

Client audio mapping can cause excessive load on servers and the network. The higher the audio quality, the more bandwidth is required to transfer the audio data. Higher quality audio also uses more server CPU to process.

Important: Client sound support mapping is not supported when connecting to Citrix XenApp for UNIX.

Associating User Device File Types with Published Applications

Receiver supports HDX Plug-n-Play content redirection. Functionally equivalent to extended parameter passing, content redirection allows you to enforce all underlying file type associations from the server, eliminating the need to configure extended parameter passing on individual user devices.

To associate file types on the user device with applications published on the server, configure Plug-n-Play content redirection on the server. For more information, see the XenApp administration topics.