Citrix XenApp and Cisco WAAS

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I recently made a design for a Citrix XenApp 6 farm that had to comply with the Cisco WAAS solution the customer had in place.  This image is from the Cisco WAAS website to clarify the set-up (although this is about XenDesktop, it uses the same principals).

One of the requirements for Cisco WAAS to fully perform is to disable compression and lower the encryption to basic. So applications have to be published with basic encryption, this encryption is not meant to be secure but just ‘scrambles’ data (CTX155541). Because of the rather basic encryption the Cisco WAAS solution is able to optimize the data transferred.

The Cisco WAAS solution claims to provide better compression than Citrix native compression according to the following graph. I’m not sure how to interpreter this ghaps because it seems that this is browser activity from a Citrix XenApp server which is HTTP traffic instead of ICA.

When I asked @CiscoWaas (great to have social media) they told me this is ICA traffic and not measured HTTP traffic from a Citrix XenApp server.

To use optimisation you need to turn compression off for optimization:

Open the “default.ica” file, located by default in “C:InetpubwwwrootCitrixXenAppconf” on your Web Interface server, with Notepad and add the entry “Compress=Off” under the Application section, then save the file.

The WAN optimization that’s delivered via Cisco WAAS is without a doubt a good reason to build such a config but this also means that when you update your Citrix Web Interface you have to add this entry again, meaning extra administrative burden when using Cisco WAAS for ICA optimization.

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