Symptoms
When authenticating through a smart card over ICA or accessing information on a smart card during a session, you experience long delays when compared to using RDP with the same devices, server, and client computers.
These delays when using smart cards with ICA can last twice as long as RDP delays under certain conditions (for example, if you have an average ping roundtrip longer than 40 milliseconds (ms)).
Cause
This occurs because of the differences in the locking mechanisms between these two protocols, some restrictions over the winscard Application Programming Interface (API), and the number of processes simultaneously accessing the smartcard.
Testing also shows that some smart card applications poll the smart card device at a very high rate. Over a slow network link, this causes delays to other transmission requests taking place.
Resolution
While Citrix is aware of this issue and will work to improve the smart card locking mechanism in future product releases, third-party smart card applications are often involved in this performance degradation.
Most of the time you can work around this issue by disabling any processes that access the smart card device, but are not required for authentication or data transmission.
