A Method for Calculating Frame Check Sequences in Tagged Ethernet Frames
Like other technologies such as Internet Protocol (IP) or Transmission Control Protocol (TCP), an Ethernet frame also has a field to detect some errors occurred on transmission. This field is referred to as Frame Check Sequence (FCS). Usually, when an Ethernet frame conveys extra information on some feature such as VLAN (Virtual Local Area Network), a field called tag is inserted into the frame and FCS must be recalculated. In this paper, the authors propose a method for calculating a frame check sequence in a tagged frame effectively. Their method utilizes the relationship between an Ethernet frame and its tagged Ethernet frame on FCS.