• Ian McDonald's avatar
    [DCCP]: Fix CCID3 · 66a377c5
    Ian McDonald authored
    This fixes CCID3 to give much closer performance to RFC4342.
    
    CCID3 is meant to alter sending rate based on RTT and loss.
    
    The performance was verified against:
    http://wand.net.nz/~perry/max_download.php
    
    For example I tested with netem and had the following parameters:
    Delayed Acks 1, MSS 256 bytes, RTT 105 ms, packet loss 5%.
    
    This gives a theoretical speed of 71.9 Kbits/s. I measured across three
    runs with this patch set and got 70.1 Kbits/s. Without this patchset the
    average was 232 Kbits/s which means Linux can't be used for CCID3 research
    properly.
    
    I also tested with netem turned off so box just acting as router with 1.2
    msec RTT. The performance with this is the same with or without the patch
    at around 30 Mbit/s.
    
    Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    66a377c5
packet_history.h 5.59 KB