Wireshark-users: Re: [Wireshark-users] Checksum incorrect on the IP layer on RTP packets
Wynns, Roger [OXFORD] wrote:
Have a look at TCP checksum offloading :-)

(http://wiki.wireshark.org/TCP_checksum_offload)

Roger



Also see:

http://www.wireshark.org/docs/wsug_html_chunked/ChAdvChecksums.html

Section 7.8.2