	US 7,606,166 B2
	System and method for computing a blind checksum in a host ethernet adapter (HEA)
Claude Basso, Raleigh, N.C. (US); Jean Louis Calvignac, Raleigh, N.C. (US); Chih-jen Chang, Apex, N.C. (US); Philippe Damon, Raleigh, N.C. (US); Ronald Edward Fuhs, Rochester, Minn. (US); Natarajan Vaidhyanathan, Carrboro, N.C. (US); Fabrice Jean Verplanken, La Gaude (France); Colin Beaton Verrilli, Apex, N.C. (US); and Scott Michael Willenborg, Stewartville, Minn. (US)
Assigned to International Business Machines Corporation, Armonk, N.Y. (US)
Filed on Apr. 01, 2005, as Appl. No. 11/97,430.
Prior Publication US 2006/0221969 A1, Oct. 05, 2006
Int. Cl. H04L 12/66 (2006.01)

U.S. Cl. 370—252 [370/392]

15 Claims

1. A method for computing a blind checksum in a host Ethernet adapter (HEA) comprising:

receiving a packet in the HEA;

determining whether the packet is in Internet protocol version four (IPv4) the packet having an IP header;

computing by the HEA, if the packet is not in IPv4, the checksum of the packet;

determining, if the packet is in IPv4, whether the packet is in transmission control protocol (TCP) or user datagram protocol (UDP);

parsing the packet for a source address and a destination address;

building the pseudo-header with the source address and the destination address;

giving the pseudo-header a length of the product of the IP header length field in the IPv4 Header with the number four, subtracted from the “Total Length” field in the IP header;

attaching, if the packet is in IPv4 and not in either of TCP or UDP, the pseudo-header to the packet; and

computing by the HEA, if the packet is in IPv4 and not in either of TCP or UDP, the checksum of the packet based on the pseudo-header and the IPv4 standard.