Patent ID: 7489706

Claim:
A method of placing timestamp information in a frame, said frame including a first portion and a second portion wherein said first portion is contained within said second portion and wherein said first portion is processable at a selected protocol layer of a protocol stack and said second portion is processable subsequently thereto at a lower protocol layer of said protocol stack at which a numerically computed error detection code for said second portion is computed, said method comprising steps of: embedding a timestamp signature in said first portion during processing thereof at said selected protocol layer, said timestamp signature having a timestamp subfield of initialized data and a corrector subfield of initialized data wherein a numerical constant functionally equivalent to said numerically computed error detection code is determinable from said initialized data in said timestamp subfield and said corrector subfield; modifying said data in said timestamp subfield with said timestamp information wherein said timestamp subfield modifying step is performed subsequently to processing of said second portion at said lower protocol layer; and modifying said data in said corrector subfield subsequently to said timestamp subfield modifying step such that said numerical constant as determinable from said modified data in said timestamp subfield and said corrector subfield remains unchanged whereby said numerically computed error detection code computed at said lower protocol layer remains valid.