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Dear all,
I'm doing a quite exhaustive analysis of the TCP
implementation within 2.2.x kernel, and I have found an specific issue that I'm
not able to solve by myself. I know that now you will spend your effort in the
2.4.x kernel. However I would like to share my doubt with you and I would really
appreciate any piece of help with it.
When a Duplicate ACK arrives, the tcp_fast_retrans
function is called. Aparentely, this function does not trigger any
retransmission unless tp->dup_acks == 3 or tp->fackets_out > 3. In some
ocassions this is the behaviour I see (by tcpdump captures), but in other cases,
the first dupack triggers a retransmission, although the number of sacked
segments is only two. I have tried to see why this retransmission is trigerred,
but I can't find it. Can anybody put some light in this tunnel :-)
?
Thanks in advance and regards.
Ramón
PD.- Please I wish to be personally CC'ed the
answers/comments posted to the list in response to my
posting
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