Error detection EDC= Error Detection and Correction bits (redundancy) D Data protected by error checking, may include header fields Error detection not 100% reliable Protocol may miss some errors, but rarely Larger edc field yields better detection and correction datagram datagram all bits in d N OK detected error d data bits- D EDC D EDC bit-error prone link 5: DatError Detection 5: DataLink Layer 5-7 EDC= Error Detection and Correction bits (redundancy) D = Data protected by error checking, may include header fields • Error detection not 100% reliable! • Protocol may miss some errors, but rarely • Larger EDC field yields better detection and correction