Help Server<->Client communication and packet structures

A couple of questions for the L2OFF devs out there:
1. Where are the packets encoded and decoded (or their structure saved) in the core, in the sense of - is there a file which lists the structure of packets, similar to L2J or the UIPacket.uc in the interface?
2. Is it possible to track (and record) SERVER<->CLIENT packet communication/exchange, and if so could you share how?