Cisco Unified Contact Center Enterprise Solution Reference ...
Cisco Unified Contact Center Enterprise Solution Reference ...
Cisco Unified Contact Center Enterprise Solution Reference ...
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Chapter 3 Design Considerations for High Availability<br />
OL-8669-05<br />
<strong>Cisco</strong> <strong>Unified</strong> CallManager and CTI Manager Design Considerations<br />
Figure 3-5 CTI Manager Device Request to a Remote <strong>Cisco</strong> <strong>Unified</strong> CallManager<br />
ICM<br />
PG<br />
Subscriber<br />
(CTI Manager<br />
and<br />
<strong>Cisco</strong><br />
CallManager)<br />
Request: IPCC<br />
agent ext. 101<br />
Device not on local<br />
<strong>Cisco</strong> CallManager<br />
Publisher<br />
(CTI Manager<br />
and<br />
CallManager)<br />
Forward request<br />
Subscriber<br />
(CTI Manager<br />
and<br />
<strong>Cisco</strong><br />
CallManager)<br />
Device<br />
found<br />
IP IP<br />
IP phone ext. 100<br />
IP phone ext. 101<br />
Although it might be tempting to register all of the <strong>Unified</strong> CCE devices to a single subscriber in the<br />
cluster and point the Peripheral Gateway (PG) to that server, this configuration would put a high load on<br />
that subscriber. If the PG were to fail in this case, the duplex PG would connect to a different subscriber,<br />
and all the CTI Manager messaging would have to be routed across the cluster to the original subscriber.<br />
It is important to distribute devices and CTI applications appropriately across all the call processing<br />
nodes in the <strong>Cisco</strong> <strong>Unified</strong> CallManager cluster to balance the CTI traffic and possible failover<br />
conditions.<br />
The external CTI applications use a JTAPI user account on the CTI Manager to establish a connection<br />
and assume control of the <strong>Cisco</strong> <strong>Unified</strong> CallManager devices registered to this JTAPI user. In addition,<br />
given that the CTI Managers are independent from each other, any CTI application can connect to any<br />
CTI Manager to perform its requests. However, because the CTI Managers are independent, one CTI<br />
Manager cannot pass the CTI application to another CTI Manager upon failure. If the first CTI Manager<br />
fails, the external CTI application must implement the failover mechanism to connect to another CTI<br />
Manager in the cluster.<br />
For example, the Agent PG handles failover for the CTI Manager by using its duplex servers, sides A<br />
and B, each of which is pointed to a different subscriber in the cluster, but not at the same time. The PG<br />
processes are designed to prevent both sides from trying to be active at the same time. Additionally, both<br />
of the duplex PG servers use the same JTAPI user to log into the CTI Manager applications. However,<br />
only one <strong>Cisco</strong> <strong>Unified</strong> CallManager PG side allows the JTAPI user to register and monitor the user<br />
devices to conserve system resources in the <strong>Cisco</strong> <strong>Unified</strong> CallManager cluster. The other side of the<br />
<strong>Cisco</strong> <strong>Unified</strong> CallManager PG stays in hot-standby mode, waiting to be activated immediately upon<br />
failure of the active side.<br />
Figure 3-6 shows two external CTI applications using the CTI Manager, the Agent PG, and the<br />
<strong>Unified</strong> IP IVR (CRS). The <strong>Cisco</strong> <strong>Unified</strong> CallManager PG logs into the CTI Manager using the JTAPI<br />
account User 1, while the <strong>Unified</strong> IP IVR (CRS) uses account User 2. Each external application uses its<br />
own specific JTAPI user account and will have different devices registered and monitored by that user.<br />
For example, the <strong>Cisco</strong> <strong>Unified</strong> CallManager PG (User 1) will monitor all four agent phones and the<br />
inbound CTI Route Points, while the <strong>Unified</strong> IP IVR (User 2) will monitor its CTI Ports and the CTI<br />
Route Points used for its JTAPI Triggers. Although multiple applications could monitor the same<br />
devices, this method is not recommended because it can cause race conditions between the applications<br />
trying to take control of the same physical device.<br />
76604<br />
<strong>Cisco</strong> <strong>Unified</strong> <strong>Contact</strong> <strong>Center</strong> <strong>Enterprise</strong> 7.x SRND<br />
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