Summary of magic trace values:

fcfcfcfc - SPUD I/O Completions
fefefefe - All I/O Completions
fafafafa - SPUD (Transmit|Send)AndRecv completion
fdfdfdfd - SPUD (Transmit|Send)AndRecv completion upcall to client occurs
fbfbfbfb - TransmitFileAndRecv status code


a, c, d, and e are all in AtqpProcessContext (atqsupp.cxx)
b is in                   I_AtqTransmitFileAndRecv (spud.cxx)

more detail as I get to it..