Cisco Cisco Unified Contact Center Enterprise 9.0(2) Design Guide
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Cisco Unified Contact Center Enterprise 7.0, 7.1, and 7.2 SRND
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Chapter 3 Design Considerations for High Availability
Peripheral Gateway Design Considerations
The Agent PG Peripheral Interface Manager (PIM) is also a node-managed process and is monitored for
unexpected failures and automatically restarted. This process manages the higher-level interface
between the Unified ICM and the Unified CM cluster, requesting specific objects to monitor and
handling route requests from the Unified CM cluster.
unexpected failures and automatically restarted. This process manages the higher-level interface
between the Unified ICM and the Unified CM cluster, requesting specific objects to monitor and
handling route requests from the Unified CM cluster.
In a duplex Agent PG environment, both JTAPI services from both Agent PG sides log into the CTI
Manager upon initialization. Unified CM PG side A logs into the primary CTI Manager, while PG side
B logs into the secondary CTI Manager. However, only the active side of the Unified CM PG registers
monitors for phones and CTI route points. The duplex Agent PG pair works in hot-standby mode, with
only the active PG side PIM communicating with the Unified CM cluster. The standby side logs into the
secondary CTI Manager only to initialize the interface and make it available for a failover. The
registration and initialization services of the Unified CM devices take a significant amount of time, and
having the CTI Manager available significantly decreases the time for failover.
Manager upon initialization. Unified CM PG side A logs into the primary CTI Manager, while PG side
B logs into the secondary CTI Manager. However, only the active side of the Unified CM PG registers
monitors for phones and CTI route points. The duplex Agent PG pair works in hot-standby mode, with
only the active PG side PIM communicating with the Unified CM cluster. The standby side logs into the
secondary CTI Manager only to initialize the interface and make it available for a failover. The
registration and initialization services of the Unified CM devices take a significant amount of time, and
having the CTI Manager available significantly decreases the time for failover.
In duplex PG operation, the side that goes active is the PG side that is first able to connect to the Unified
ICM Call Router Server and request configuration information. It is not deterministic based upon the
side-A or side-B designation of the PG device, but it depends only upon the ability of the PG to connect
to the Call Router, and it ensures that only the PG side that has the best connection to the Call Router
will attempt to go active.
ICM Call Router Server and request configuration information. It is not deterministic based upon the
side-A or side-B designation of the PG device, but it depends only upon the ability of the PG to connect
to the Call Router, and it ensures that only the PG side that has the best connection to the Call Router
will attempt to go active.
The startup process of the PIM requires that all of the CTI route points be registered first, which is done
at a rate of 5 route points per second. For systems with a lot of CTI route points (for example, 1000),
this process can take as long as 3 minutes to complete before the system will allow any of the agents to
log in. This time can be reduced by distributing the devices over multiple PIM interfaces to the
Unified CM cluster.
at a rate of 5 route points per second. For systems with a lot of CTI route points (for example, 1000),
this process can take as long as 3 minutes to complete before the system will allow any of the agents to
log in. This time can be reduced by distributing the devices over multiple PIM interfaces to the
Unified CM cluster.
Unified CM will accept multiple PG/PIM connections on a single cluster, which allows Unified CCE to
distribute different types of registrations across multiple connections. For example, one PIM could be
configured to log in as JTAPIuser1 and have only the CTI route points associated with it, while a second
PIM could be logged in as JTAPIuser2 and have the agent IP phones registered to it. This arrangement
would allow agents to log in faster at startup, without having to wait for the dialed numbers to be
registered with CTI Manager first.
distribute different types of registrations across multiple connections. For example, one PIM could be
configured to log in as JTAPIuser1 and have only the CTI route points associated with it, while a second
PIM could be logged in as JTAPIuser2 and have the agent IP phones registered to it. This arrangement
would allow agents to log in faster at startup, without having to wait for the dialed numbers to be
registered with CTI Manager first.
Unified CM Failure Scenarios
A fully redundant Unified CCE system contains no single points of failure. However, there are scenarios
where a combination of multiple failures can reduce Unified CCE system functionality and availability.
Also, if a component of the Unified CCE solution does not itself support redundancy and failover,
existing calls on that component will be dropped. The following failure scenarios have the most impact
on high availability, and Unified CM Peripheral Interface Managers (PIMs) cannot activate if either of
the following failure scenarios occurs (see
where a combination of multiple failures can reduce Unified CCE system functionality and availability.
Also, if a component of the Unified CCE solution does not itself support redundancy and failover,
existing calls on that component will be dropped. The following failure scenarios have the most impact
on high availability, and Unified CM Peripheral Interface Managers (PIMs) cannot activate if either of
the following failure scenarios occurs (see
):
•
Agent PG/PIM side A and the secondary CTI Manager that services the PG/PIM on side B both fail.
•
Agent PG/PIM side B and the primary CTI Manager that services the PG/PIM on side A both fail.
In either of these cases, the Unified ICM will not be able to communicate with the Unified CM cluster.