I have used this tool a few times and I can highly recommend it
“Citrix Connection Test Tool” provides various connection methods for scalability test and other tests which require a number of sessions to be established. The tool enables testers to establish as many numbers of ICA sessions as they want by creating or duplicating session settings on Citrix Presentation Server Client.
• Citrix Presentation Server Client
• Visual Basic Runtime or manual registration of required modules
(Please read the attached document for more details.)
Using Citrix Connection Test Tool
Using “Citrix Connection Test Tool” helps those who want to run multiple connections test to Citrix Presentation Server. With this tool you can establish the desired amount of ICA sessions from one machine in effective way so that you can measure the scalability on your testing environment.
Please read the attached document “Citrix Connection Test Tool” which describes how to use the tool.