Re: [PATCH 2/2] tcp: TLP loss detection.

[David Miller <davem@davemloft.net>]

From: Neal Cardwell <ncardwell@google.com>
Date: Mon, 11 Mar 2013 17:38:12 -0400

> On Mon, Mar 11, 2013 at 4:00 PM, Nandita Dukkipati <nanditad@google.com> wrote:
>> This is the second of the TLP patch series; it augments the basic TLP
>> algorithm with a loss detection scheme.
>>
>> This patch implements a mechanism for loss detection when a Tail
>> loss probe retransmission plugs a hole thereby masking packet loss
>> from the sender. The loss detection algorithm relies on counting
>> TLP dupacks as outlined in Sec. 3 of:
>> http://tools.ietf.org/html/draft-dukkipati-tcpm-tcp-loss-probe-01
>>
>> The basic idea is: Sender keeps track of TLP "episode" upon
>> retransmission of a TLP packet. An episode ends when the sender receives
>> an ACK above the SND.NXT (tracked by tlp_high_seq) at the time of the
>> episode. We want to make sure that before the episode ends the sender
>> receives a "TLP dupack", indicating that the TLP retransmission was
>> unnecessary, so there was no loss/hole that needed plugging. If the
>> sender gets no TLP dupack before the end of the episode, then it reduces
>> ssthresh and the congestion window, because the TLP packet arriving at
>> the receiver probably plugged a hole.
>>
>> Signed-off-by: Nandita Dukkipati <nanditad@google.com>
> 
> Acked-by: Neal Cardwell <ncardwell@google.com>

Also applied, thanks.