TCP Retransmission meet some problem.

[cameled yang]

Hello, everyone.

Recently, I work with a eCos project, It's network stack using freebsd
version(Not sure Exactly version, SDK is provide by others).

Everything work fine before I meet a problem. When local http server return
packet to borwser, sometimes retransmission happened. But rarely in resent
tcp payload contain previous sented packet header! (all things are same).

cases like this:

...

Browser:      Sequence number:444,      Acknowledgment number: 4600

NetStack:    Sequence number:4600,     Acknowledgment number: 444

NetStack:    Sequence number:7819,     Acknowledgment number:444 (Previous
segment lost?)

Browser:     Sequence number:444,       Acknowledgment number: 6060

NetStack:    Sequence number:6060,     Acknowledgment number: 444
(Retansmission happened)

...

Sequence 6060 contain 7819's header(Socket cache have been changed).

I guess mbuf header of 7819's write it's protocol header info to  6060's
cluster.

Anyone know something about this?

Best Regrads.