net.ipv4.tcp_slow_start_after_idle = 1
net.ipv4.tcp_workaround_signed_windows = 0
net.ipv4.tcp_base_mss = 512
net.ipv4.tcp_mtu_probing = 0
net.ipv4.tcp_abc = 0
net.ipv4.tcp_congestion_control = bic
net.ipv4.tcp_tso_win_divisor = 3
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_max_tw_buckets_ub = 66144
net.ipv4.tcp_max_tw_kmem_fraction = 384
net.ipv4.tcp_low_latency = 0
net.ipv4.tcp_frto = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_adv_win_scale = 2
net.ipv4.tcp_app_win = 31
net.ipv4.tcp_rmem = 4096        87380   16777216
net.ipv4.tcp_wmem = 4096        65536   16777216
net.ipv4.tcp_mem = 16777216     16777216        16777216
net.ipv4.tcp_dsack = 0
net.ipv4.tcp_ecn = 0
net.ipv4.tcp_reordering = 5
net.ipv4.tcp_fack = 1
net.ipv4.tcp_orphan_retries = 0
net.ipv4.tcp_max_syn_backlog = 1024
net.ipv4.tcp_rfc1337 = 0
net.ipv4.tcp_stdurg = 0
net.ipv4.tcp_abort_on_overflow = 0
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_fin_timeout = 20
net.ipv4.tcp_retries2 = 15
net.ipv4.tcp_retries1 = 3
net.ipv4.tcp_keepalive_intvl = 75
net.ipv4.tcp_keepalive_probes = 9
net.ipv4.tcp_keepalive_time = 1000
net.ipv4.tcp_max_tw_buckets = 360000
net.ipv4.tcp_max_orphans = 131072
net.ipv4.tcp_synack_retries = 5
net.ipv4.tcp_syn_retries = 5
net.ipv4.tcp_retrans_collapse = 1
net.ipv4.tcp_sack = 0
net.ipv4.tcp_window_scaling = 0
net.ipv4.tcp_timestamps = 0

Linux ns6812.ovh.net 2.6.18-ovz-028stab048.1-enterprise #1 SMP Thu Nov 1 19:34:25 CET 2007 i686 GNU/Linu

net/ipv4/tcp_timer.c::tcp_out_of_resources()
....
        if (ub_too_many_orphans(sk, orphans)) {
                if (net_ratelimit())
                        printk(KERN_INFO "Out of socket memory\n");