Por favor, verifique "tcp_thin_dupack"
sysctl net.ipv4.tcp_thin_dupack net.ipv4.tcp_thin_dupack = 0
tcp_thin_dupack - BOOLEAN Enable dynamic triggering of retransmissions after one dupACK for thin streams. If set, a check is performed upon reception of a dupACK to determine if the stream is thin (less than 4 packets in flight). As long as the stream is found to be thin, data is retransmitted on the first received dupACK. This improves retransmission latency for non-aggressive thin streams, often found to be time-dependent. For more information on thin streams, see Documentation/networking/tcp-thin.txt