The Browser Content Redirection in a virtual environment

2019-07-11T10:55:28+02:00July 11th, 2019|

Already in 2016 the largest global companies declared a monthly use of at least 16 hours of multimedia content per worker, in practice an average of 45 minutes a day. An already significant phenomenon and in continuous increase. Videos are now used in all business sectors, such as marketing, technical support, or internal and external training.

Many of the virtual desktop infrastructures, conceived well before this explosion of multimedia contents and the sudden change of the Web, have undergone this change and had to look for solutions to face the high increase of load on the servers (in terms of CPU, RAM and use bandwidth) required by the massive use of video. On the one hand, infrastructure reinforcement was required, using higher-frequency CPUs and adding dedicated GPUs for session encoding, and on the other, the focus was on exploiting the client’s decoding capabilities using the Multimedia Redirection (which however bound to the use of Windows Media Player).

This second solution, however, has been superseded by the further evolution of the Web in which videos are provided directly in streaming on special pages. The advent of the new HTLM5 web standard reinforces this direction and, moreover, enables navigation capabilities that are graphically much more appealing but more expensive on the computational side.

To improve the use of multimedia content in a virtual environment, Citrix Virtual Apps and Desktops has recently released a new feature called Browser Content Redirection. This feature allows you to define a list of web pages (White List) so the rendering can be delegated from the virtual machine to the client, through the Citrix Workspace App, a corresponding rendering engine instantiated on the client side, which downloads the content of the page and shows it overlapping with the visual area of the browser. This operation not only makes the servers much lighter when viewing these pages, but also potentially reduces the bandwidth needed inside the data center, when the client is directly connected to the internet or can have direct access to the indicated web page.

The improvements are even more evident in the use of Citrix virtual resources on the move, with positive effects also in the end-user experience. The functionality offered by Citrix also allows it to work on a Black List basis (pages to be excluded) and is robust to any client-side issues: if this fails to recover or display the page, its rendering passes to the virtual machine.

To configure this feature, Citrix has written a detailed guide, while the client side is a feature enabled by default. I summarize the requirements in the following table:

Client       Server       Virtual Machines Browser in the VM
Citrix Workspace app 1808 (for Windows o Linux) or  greater

Citrix Receiver for Windows 4.10 greater

Citrix Receiver for Linux 13.9 greater

Citrix Virtual Apps and Desktops 7 1808 and greater

XenApp and XenDesktop 7.18, 7.17, 7.16 and greater

Windows 10 (minimum version 1607), Windows Server 2012 R2, Windows Server 2016 Google Chrome v66 and greater (it requires a specific plugin and Citrix Workspace App 1809)

Internet Explorer 11

 

Praim products can use this feature starting from the version of ThinOX (or ThinOX4PC) 10.4.1 32-bit or 11.0.2 64-bit, while on Windows terminals from version 2.6.0 for Windows 10 IoT 2016 LTSB or 3.0. 1 for Windows 10 IoT 2019 LTSC. It is possible to use this feature also on Raspberry, however I do not recommend its use due to the low availability of RAM.

Working – Praim N9152 using Browser Content Redirection

 

No Working – Praim N9152 not using Browser Content Redirection (disabled via policy)

As you can see from the videos, the use of this feature allows a considerable saving of CPU on the server side, with optimal use of the contents for the user.

However, after a few hours of use I also noticed some important peculiarities that must be taken into account:

  • On the multimedia “redirected” content, the remote audio (the system volume of the virtual machine) no longer has effect. You can adjust the video volume only through the local configurator or by using the volume within the video.
  • Depending on the video resolution and duration, the endpoint RAM consumption increases compared to a standard use with Citrix infrastructure.

Another curiosity concerns the location of the viewed pages. I happened to carry out the tests enabling the YouTube domain to be redirected by connecting me from Italy to a Citrix server in United Kingdom. Using the Browser Content Redirection the YouTube page is localized in Italian, while disabling this functionality the page is in English. This is because YouTube, through a code inside the web page, tries to provide a personalized experience for each user by going back to the geographical position of the same through the IP address from which the request comes. Enabling the Browser Content Redirection the request was made by my client with “Italian” IP, while disabling it comes from the “English” IP of the data center.