Cisco Cisco Administrative Workstation Guia Da Instalação

the same time. For example, in 

 PIMs 1 and 2 are active on Side A; PIM 

3 is active on Side B. The duplexed OPCs communicate with each other through 
the MDS to ensure that a PIM is active only on one side at a time.

The duplexed PG architecture protects against a failure on one side of the PG. For 
example, if an adapter card controlling access to an ACD fails, a hot standby PIM 
can use the alternate PIM activation path. As shown in 

, PIM3 has been 

activated from Side B of the PG. This might be in response to an adapter failure 
between the Side A PIM3 and ACD3.

In this type of failure scenario, the PG is able to maintain communication with the 
attached ACD.

Only one PG Agent actively communicates with a side of the Central Controller. 
When messages arrive at the Central Controller, they are delivered to both sides 
by the Central Controller Synchronizer process. The PG maintains idle 
communication paths to both sides of the Central Controller in case a switch-over 
to the other side of the Central Controller or PG is necessary.

A maximum of two PGs can run on a single hardware platform. A single PG can 
serve only one type of ACD, but can also (as of ICM 5.0) contain one or more 
VRU PIMs and/or Media Routing PIMs provided that the server hardware has the 
capacity to support the aggregate processing load. For a single hardware platform 
to serve two different types of ACDs, you need two PGs—one for each peripheral 
type. 

 shows some possible PG options.