TCP messages go OUT OF ORDER on FreeBSD 7

[Yony Yossef]

Hi All.

I'm working on a 10GigE driver for FreeBSD 7, supporting both LRO and TSO
(LSO).

I get a stable connection enabling LRO alone and TSO alone, but when I
enable both offloads I get OUT OF ORDER packets on the sender side.
Meaning the sending OS sends the same packet several times without getting
any ACKs in between. The wireshark timestamps show that the sender did not
even wait too long in order to retransmit the packets, there is only a 10-20
microsecs gap between the first and second sends of the same packet.

I'm a TCP/IP newbee, can anybody explain to me how can this happen?

Yony