Patent ID: 6014767
Filing Date: 2000-01-11
Classification: H03M

Abstract:
A method for generating a packet, the integrity of which may be checked upon receipt at a destination node to which the packet is sent through a packet network, said method comprising the steps of:calculating a FCS (Frame Check Sequence) value based on CRC (Cylical Redundancy Check) code generated by the polynomial generator of degree 10, G10(X)=X.sup.10 +X.sup.9 +X.sup.5 +X.sup.4 +X+1, of a packet payload bycalculating (520) CRC code generated by the polynomial generator of degree 9, G9(d)=X.sup.9 +X.sup.4 +1, of the packet payload and storing the resulting 9-bit stream FCS in 9-bit storage means,calculating (510) the parity of said payload,setting (580) the most significant bit of a 10-bit storage to zero,if the payload parity is odd (590), adding (597) the 9-bit stream FCS to a bit stream representation of the generator polynomial of degree 9, G9(X)and storing the 10-bit stream resulting from the addition of the previous step in the 10-bit storage means, this stored 10-bit stream representing the payload FCS,if the payload parity is even, storing (595) the 9-bit stream FCS in the least significant bits of the 10-bit storage means, the 10-bit stream of the 10-bit storage means representing the payload FCS;retrieving the packet for which the foregoing calculations were performed and the 10-bit stream representing the payload FCS; andgenerating a packet suitable for transmission by adding the retrieved payload FCS to the payload of the retrieving packet.