The PCAP schema has a MagicNumber element with type xs:hexBinary. Tests are performed on this to determine the endianness of the data. It does this by converting the hexBinary to a string and then comparing against a string, i.e.

xs:string(.) eq 'ABCDEF'

String conversion shouldn't be necessary, so I modified to to use xs:hexBinary insteat, i.e.

. eq xs:hexBinary('ABCDEF')

This should work, is more readable, and should be slightly more efficient since it doesn't need to convert the hexBinary value to a string. However, this always fails comparison. We need to investigate why this fails and fix it so that we can do hexBinary comparisons.