Citrix Virtual Apps and Desktops acceleration


In this discussion, Virtual Apps refers to the ICA and CGP protocol streams. Therefore, what is said about Virtual Apps applies also to Virtual Desktops.

Virtual Apps/Virtual Desktops (ICA/CGP) acceleration has three components:

  • Compression–The appliance cooperates with Virtual Apps clients and servers to compress Virtual Apps data streams for interactive data (keyboard/mouse/display/audio) and batch data (printing and file transfers). This interaction takes place transparently and requires no configuration of the appliance. A small amount of configuration, described below, is required on older Virtual Apps servers (release 4.x).

  • Multistream ICA–In addition to compression, Citrix SD-WAN WANOP appliances support the new Multistream ICA protocol, in which up to four connections are used for the different ICA priorities, instead of multiplexing all priorities over the same connection. This approach gives interactive tasks greater responsiveness, especially when combined with the appliance’s traffic shaping.

  • Traffic shaping–The Citrix SD-WAN WANOP traffic shaper uses the priority bits in the Virtual Apps data protocols to modulate the connection’s priority in real time, matching the bandwidth share of each connection to what the connection is transmitting at the moment.


    Multistream ICA is disabled by default. It can be enabled on the Features page. Multi-Stream ICA and AutoQoS requires Session Reliability to be enabled.

To optimize ICA connections for Citrix Virtual Apps and Desktops release 7.0 and later, Citrix SD-WAN WANOP appliance supports Citrix Receiver for Chrome release 1.4 and later, and Citrix Receiver for HTML5 release 1.4 and later.

HDX Transport protocol from UDP/EDT to TCP – In certain network conditions, UDP/EDT cannot be used as the optimized protocol to deliver HDX traffic. You can change the protocol to TCP so that WANOP can provide:

  • Compression/DDup benefits
  • Visibility (local reports and HDX Insight)

WANOP can block EDT traffic and force the session to TCP. During session initiation Citrix Receiver starts session on both TCP and EDT. If EDT session is not established then TCP session is used. WANOP GUI provides an option to force the session on TCP protocol on the features page.

Citrix Virtual Apps and Desktops acceleration