Cisco Unified Contact Center Enterprise Solution Reference ...
Cisco Unified Contact Center Enterprise Solution Reference ...
Cisco Unified Contact Center Enterprise Solution Reference ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Understanding Failure Recovery<br />
<strong>Unified</strong> ICM<br />
3-36<br />
<strong>Cisco</strong> <strong>Unified</strong> <strong>Contact</strong> <strong>Center</strong> <strong>Enterprise</strong> 7.x SRND<br />
Chapter 3 Design Considerations for High Availability<br />
The <strong>Unified</strong> ICM is a collection of services and processes running on <strong>Unified</strong> ICM servers. The failover<br />
and recovery process for each of these services is unique and requires carefully examination to<br />
understand the impact to other parts of the <strong>Unified</strong> CCE solution, including another <strong>Unified</strong> ICM service.<br />
As stated previously, all redundant <strong>Unified</strong> ICM servers discussed in this chapter must be located at the<br />
same site and connected through a local private LAN or crossover cable. You can provide the private<br />
LAN by installing a second network interface card (NIC) in each server (sides A and B) and connecting<br />
them with a crossover cable. By doing so, you can eliminate all external network equipment failures.<br />
<strong>Cisco</strong> <strong>Unified</strong> CallManager PG and CTI Manager Service<br />
When the active CTI Manager Service or PG software fails, the PG JTAPI Gateway/PIM detects an<br />
OUT_OF_SERVICE event and induces a failover to the redundant (duplex) PG. Because the redundant<br />
PG is logged into the backup <strong>Cisco</strong> <strong>Unified</strong> CallManager subscriber CTI Manager Service already, it<br />
registers the IP phones and configured dialed numbers or CTI route points automatically. This<br />
initialization service takes place at a rate of about 5 devices per second. The agent desktops show them<br />
as being logged out or not ready, and a message displays stating that their routing client or peripheral<br />
(<strong>Cisco</strong> <strong>Unified</strong> CallManager) has gone off-line. (This warning can be turned on or off, depending on the<br />
administrator's preference.) All agents lose their desktop third-party call control functionality until the<br />
failure recovery is complete. The agents can recognize this event because call control action buttons on<br />
the desktop will gray out, and they will not be able to do anything with the desktop. Any existing calls<br />
should remain active without any impact to the caller.<br />
Note Agents should not push any buttons during desktop failover because these keystrokes can be buffered<br />
and sent to the CTI server when it completes its failover and restores the agent states.<br />
Once the CTI Manager service or PG completes its failover, the agents return to their previous state. At<br />
this point, the agents should also be able to release, transfer, or conference calls.<br />
<strong>Unified</strong> ICM Voice Response Unit PG<br />
When a Voice Response Unit (VRU) PG fails, all the calls currently in queue or treatment on that<br />
<strong>Unified</strong> IP IVR (CRS) are dropped. Calls queued in the <strong>Unified</strong> CVP are not dropped and will be<br />
redirected to a secondary CVP or number in the H.323 dial plan, if available. The redundant (duplex)<br />
VRU PG side will connect to the <strong>Unified</strong> IP IVR (CRS) or CVP and begin processing calls upon failover.<br />
Upon recovery of the failed VRU PG side, the currently running VRU PG continues to operate as the<br />
active VRU PG. Therefore, having redundant VRU PGs adds significant value because it allows an<br />
IP IVR or CVP to continue to function as an active queue point or to provide call treatment. Without<br />
VRU PG redundancy, a VRU PG failure would block use of that IP IVR even though the IP IVR is<br />
working properly. (See Figure 3-21.)<br />
OL-8669-05