diff options
Diffstat (limited to 'src/vnet/tcp/tcp_newreno.c')
| -rw-r--r-- | src/vnet/tcp/tcp_newreno.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/src/vnet/tcp/tcp_newreno.c b/src/vnet/tcp/tcp_newreno.c index 3525f4e5918..c66250e41ea 100644 --- a/src/vnet/tcp/tcp_newreno.c +++ b/src/vnet/tcp/tcp_newreno.c @@ -51,9 +51,23 @@ newreno_rcv_cong_ack (tcp_connection_t * tc, tcp_cc_ack_t ack_type) } else if (ack_type == TCP_CC_PARTIALACK) { - tc->cwnd -= tc->bytes_acked; - if (tc->bytes_acked > tc->snd_mss) - tc->bytes_acked += tc->snd_mss; + /* RFC 6582 Sec. 3.2 */ + if (!tcp_opts_sack_permitted (&tc->rcv_opts)) + { + /* Deflate the congestion window by the amount of new data + * acknowledged by the Cumulative Acknowledgment field. + * If the partial ACK acknowledges at least one SMSS of new data, + * then add back SMSS bytes to the congestion window. This + * artificially inflates the congestion window in order to reflect + * the additional segment that has left the network. This "partial + * window deflation" attempts to ensure that, when fast recovery + * eventually ends, approximately ssthresh amount of data will be + * outstanding in the network.*/ + tc->cwnd = (tc->cwnd > tc->bytes_acked) ? + tc->cwnd - tc->bytes_acked : 0; + if (tc->bytes_acked > tc->snd_mss) + tc->cwnd += tc->snd_mss; + } } } |