Cisco Cisco IPCC Web Option Design Guide

Agents should not push any buttons during desktop failover because these keystrokes can be buffered 
and sent to the CTI server when it completes its failover and restores the agent states.

When an active PG fails-over to the idle side, calls still in progress will be recovered by querying 
Unified CM as part of the activation sequence. There will be two Termination Call Detail records 
providing information on the call prior to and after the PG transition. Peripheral call variables and ECC 
variables will be lost on the agent desktop. Indication of whether the call was a barge-in or a conference 
call will be lost on the agent desktop and in reports. Calls that were in the wrap-up state will not be 
recovered. Agents will be able to release, transfer, or conference calls from their agent desktop after 
activation completes.

Call and agent state information might not be complete at the end of a failover if there are call status and 
agent state changes during the failover window.

When a Voice Response Unit (VRU) PG fails, all the calls currently in queue or treatment on that 
Unified IP IVR are dropped. Calls in progress or queued in Unified CVP are not dropped and will be 
redirected to a secondary Unified CVP or to a number in the H.323 or SIP dial plan, if available, by the 
Survivability TCL script in the voice gateway. The redundant (duplex) VRU PG side will connect to the 
Unified IP IVR or CVP and begin processing calls upon failover. Upon recovery of the failed VRU PG 
side, the currently running VRU PG continues to operate as the active VRU PG. Therefore, having 
redundant VRU PGs adds significant value because it allows an IP IVR or CVP to continue to function 
as an active queue point or to provide call treatment. Without VRU PG redundancy, a VRU PG failure 
would block use of that IP IVR even though the IP IVR is working properly. (See