id in BRM1 should be the identity for replying party website. For example, for bing.com, it is 264960; for msn.com, it is 1184; and for hotmail.com, it is 64855.
lc in BRM1 is a constant. It is always 1033.
ct in BRM1 should be timestamp: the value in raw trace1 < trace2 < trace3, and the time of capturing of the trace is trace1 < trace2 < trace3, meaning that the value is increasing according to time.