A good tool to use to get ladder diagrams on SIP messaging from CVP and gateway/Cube side is Translator-X. Makes it a lot more readable.
Mind Contact Center Enterprise comprises a lot of components. Knowing what is going on at which point of the call/chat/mail is essential. Without this you will drown in logs. Make sure you use RTMT and add all items on UCCE/CUCM and Unity Connection to the RTMT analysis manager. Simplifies the log collection and makes sure all times are correct.