The PG basically allows UCCE to interface with other components, such as IPIVR and CUCM (called Peripherals) or third party applications. Calls arrive at the PG through trunks that are organised in trunk groups.
On the UCCE AW you can browse the configured peripherals, if you go to Configuration manager>PG Explorer. Figure 1 is an example of the PG Explorer window.
|Figure 1 - PG Explorer|
This shows a PG's Logical Controller with 3 Peripherals; one CUCM and two IPIVR Peripherals. As you can see the PCCM_PIM1 is a peripheral with CUCM as client type, contrary to the two IPIVR Peripherals that have client type VRU.
Please note that there are no IP addresses stated in the PG explorer, this is because that definition takes place during the installation of UCCE.