In EasyCall 2.1, Citrix introduced the very first Citrix virtual appliance.  Citrix will soon discontinue the EasyCall hardware appliances. Which means customers can download the EasyCall VA for free and run on top of XenServer express, which is also free!  Login is requred at  ">http://www.citrix.com/English/ss/downloads/results.asp?productID=683164 

Some bullet points..

•First Citrix virtual appliance
•Simplified evaluation and demonstration
•Based on XenServer 5
•Reduced deployment and management costs
•Increased capacity
  •Failover
•Multiple Gateway Administration
•Capacity for large customers