• Nandita Dukkipati's avatar
    tcp: TLP loss detection. · 9b717a8d
    Nandita Dukkipati authored
    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: default avatarNandita Dukkipati <nanditad@google.com>
    Acked-by: default avatarNeal Cardwell <ncardwell@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    9b717a8d
tcp_timer.c 18.3 KB