The Peripheral Gateway is the set of software processes that integrate a peripheral (ACD, IVR, CVP, CUCM) with ICM. The process that is specific to the peripheral is the PIM (Peripheral Interface Monitor). In the case of CUCM, an additional process is required - the JTAPI Gateway. Look in the appropriate PG directory - something like \icm\\PGxx\logs. You will need dumplog to interpret the binary .ems files.
ICM does not talk to the gatekeeper and knows nothing about it - the VB (Voice Browser) in CVP, now called the H.323 Service, is the only ICM/CVP process that talks to the Gatekeeper.
If you have a CVP error, the first port of call is the Error log in \Cisco\CVP\logs. Even without extended tracing levels, errors will write in the CVP log and the Error log in this directory.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.