Citrix XenDesktop ICA Optimizations And Tweaks!

Optimization for WAN ICA settings

Edit the default.ica located under ‘C:\Inetpub\wwwroot\<Site Directory>\conf’ with the following additions:

Under [WFClient] add the following:
· CPMAllowed=Off

Disables LPT Port redirection

· VSLAllowed=Off

Disabled the Printing Virtual Channel associated with LPT redirection

· UpdatesAllowed=Off

Disables Client update functionality

· OutBufCountHost=118

· OutBufCountHost2=118

This setting affects the max amount of server to client data that the connection will try and keep active at any point.

· OutBufCountClient=118

· OutBufCountClient2=118

This setting affects the max amount of client to server data that the connection will try and keep active at any point.

· OutBufLength=512

This setting aligns with the underlying packet size for wireless networks. Citrix testing has found this value to be the optimum value for most networks.

· PersistentCacheEnabled=On

Enabling the persistent cache decreases logon time and improves the performance of graphics operations during an ICA session

· MouseTimer=200

· KeyboardTimer=50

Enabling these parameters reduces the number of small mouse and keyboard packets sent to the server.

Intermediate mouse packets are discarded and a number of keystroke packets are coalesced into a single larger packet.

· ConnectionBar=0

Enables Full Screen only mode.
Under [Application] add the following:
· MaximumCompression=On

· Compress=On

Enables Maximum Data Compression

· ZLMouseMode=1

· ZLKeyBoardMode=1

These values enable SpeedScreen3 Latency reduction features



To improve ICA latency and performance, the customer tested reducing the ICA packet size (default 1460 bytes) to 512 bytes. This was accomplished by the following changes.

1. Server-side ICA packet changes may be implemented by defining the entry as a DWORD parameter (for example, 512). Restart the server for this registry value to take effect. If the entry is undefined, has a value of zero, or a value greater than 1460, it will have no effect. But other values will cause the server to use a smaller maximum length for all packets sent after session initialization.


2. Client-side ICA packet changes may be implemented by editing the users APPSRV.INI file. These changes will take effect upon the next log on. * 


* User must log off all active and disconnected sessions; restart of the Presentation Server is recommended.


 Sources:,, and


About PiroNet

Didier Pironet is an independent blogger and freelancer with +15 years of IT industry experience. Didier is also a former VMware inc. employee where he specialised in Datacenter and Cloud Infrastructure products as well as Infrastructure, Operations and IT Business Management products. Didier is passionate about technologies and he is found to be a creative and a visionary thinker, expressing with passion and excitement, hopefully inspiring and enrolling people to innovation and change.
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s