Mismatch detection in SDH frame trace identifiers

A mismatch detection method for trace identifiers contained in frames, in particular SDH-coded data frames, within a telecommunication network, wherein received trace identifiers are compared with expected trace identifiers in determined locations of the telecommunication network, for verifying if a misconnection event has occurred and generating a corresponding alarm signal, said method comprising the following steps:

• a) validating a received trace identifier and issuing a corresponding validation signal;
• b) in parallel with step a), comparing the received trace identifier with an expected trace identifier (ETI) and issuing a corresponding match signal;
• c) evaluating the validation signal and the match signal;
• and
• d) generating a matching state signal according to the result of said evaluation as per step c), wherein steps a) to d) are provided both for 16-byte length trace identifiers and 1-byte length trace identifiers, and wherein the validating step is carried out through a Cyclic Redundancy Code check in case of 16-byte length trace identifiers and a Persistency Check in case of 1-byte length trace identifiers.