In answer to your question, Yes, I have applied SR1 to an HA environment running UCCX 4.0(5). Although you may be running in an HA environment, Cisco always recommends patching/upgrading is done during off peak hours to ensure your production environment is minimally affected. No where in the below documentation

http://www.cisco.com/univercd/cc/td/doc/product/voice/sw_ap_to/apps_4_0/english/administ/crs405ig.pdf

will you find that call processing will not be interrupted. You may be however, referring to the Note found on page 253, in which the documentation states the following: "Note If your deployment includes high availability, the following procedure ensures

that your system fails over during the upgrade." If so, please understand that Cisco is merely pointing out that your server and the services that are currently running on that server will failover to the warm Standby server upon reboot. However, any IP Phone Agent that is registered with the Master UCCX server will be disconnected and must sign on to the Secondary IP Phone Agent service when the warm Standby Server becomes the active Master Server. This also affects Cisco Agent Desktop user's as well as they will receive a brief message on their desktop stating that they have been disconnected from the Chat server until they are re-registered to the Warm Standby Server.

In Summary, please always, if possible, perform any patching/upgrades/maintenance during off peak hours to ensure your production environment is minimally affected.

Best Regards,

Sam O.

Cisco Systems

Technical Assistance Center