我有一台运行 Ubuntu 的服务器，我在其中安装了 Plex Media Server。该服务器有一个 Armhf 处理器和 2GB RAM。
我的下载速度有问题。服务器有 250Mbits 链接，我的机器和服务器之间的延迟约为 25ms（如 ping 所示）。
下载速度限制在 635KB/s 左右，当我调整设置，添加
net.core.rmem_max=33554432
net.core.wmem_max=33554432
net.ipv4.tcp_rmem=4096 33554432 33554432
net.ipv4.tcp_wmem=4096 33554432 33554432
net.ipv4.tcp_window_scaling=1
net.ipv4.tcp_adv_win_scale = 31
下载速度有时会达到 835KB/s 左右。一年前，当我的网络不太好时，速度上限为 550KB/s。如果我使用多线程流，我可以将速度提高到最大。
我运行 tcpdump 来调查，使用以下命令：
tcpdump -i eth0 -s 0 'tcp port 32400' -v -nn
下载速度现在约为 5MB/s，这是我正在流式传输的视频的比特率。当我停止 tcpdump 时，速度下降到 835KB/s 左右
仅当通过 Android 应用程序进行流式传输时，我才会看到这种行为，但通过 LG TV 应用程序进行流式传输时则不会看到这种行为。
以下是通过电视应用程序播放流媒体时 tcpdump 的输出
SERVER_IP.32400 > HOME_IP.59796: Flags [.], cksum 0xd313 (incorrect -> 0x3045), seq 52636:54084, ack 1561, win 32, options [nop,nop,TS val 3236840404 ecr 1397725], length 1448
12:08:02.338704 IP (tos 0x0, ttl 64, id 41187, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59796: Flags [.], cksum 0xd313 (incorrect -> 0x4403), seq 54084:55532, ack 1561, win 32, options [nop,nop,TS val 3236840404 ecr 1397725], length 1448
12:08:02.338727 IP (tos 0x0, ttl 64, id 41188, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59796: Flags [.], cksum 0xd313 (incorrect -> 0xa9cc), seq 55532:56980, ack 1561, win 32, options [nop,nop,TS val 3236840404 ecr 1397725], length 1448
12:08:02.338734 IP (tos 0x0, ttl 64, id 41189, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59796: Flags [.], cksum 0xd313 (incorrect -> 0xc291), seq 56980:58428, ack 1561, win 32, options [nop,nop,TS val 3236840404 ecr 1397725], length 1448
12:08:02.341785 IP (tos 0x0, ttl 53, id 32606, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59796 > SERVER_IP.32400: Flags [.], cksum 0x74ac (correct), ack 39604, win 870, options [nop,nop,TS val 1397727 ecr 3236840402], length 0
12:08:02.347411 IP (tos 0x0, ttl 53, id 31812, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59794 > SERVER_IP.32400: Flags [.], cksum 0x2003 (correct), ack 11030, win 661, options [nop,nop,TS val 1397727 ecr 3236840402], length 0
12:08:02.348702 IP (tos 0x0, ttl 64, id 41190, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59796: Flags [P.], cksum 0xd313 (incorrect -> 0x2b1e), seq 58428:59876, ack 1561, win 32, options [nop,nop,TS val 3236840405 ecr 1397727], length 1448
12:08:02.348723 IP (tos 0x0, ttl 64, id 41191, offset 0, flags [DF], proto TCP (6), length 1426)
SERVER_IP.32400 > HOME_IP.59796: Flags [P.], cksum 0xd2c9 (incorrect -> 0x4c36), seq 59876:61250, ack 1561, win 32, options [nop,nop,TS val 3236840405 ecr 1397727], length 1374
12:08:02.355628 IP (tos 0x0, ttl 53, id 9026, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59797 > SERVER_IP.32400: Flags [.], cksum 0x43c4 (correct), ack 788, win 291, options [nop,nop,TS val 1397728 ecr 3236840399], length 0
12:08:02.382258 IP (tos 0x0, ttl 53, id 32607, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59796 > SERVER_IP.32400: Flags [.], cksum 0x20ec (correct), ack 61250, win 660, options [nop,nop,TS val 1397731 ecr 3236840402], length 0
12:08:02.432111 IP (tos 0x0, ttl 53, id 49296, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.60202 > SERVER_IP.32400: Flags [.], cksum 0x7eb3 (correct), ack 729, win 216, options [nop,nop,TS val 22239017 ecr 3236840397], length 0
12:08:02.432171 IP (tos 0x0, ttl 64, id 53129, offset 0, flags [DF], proto TCP (6), length 377)
SERVER_IP.32400 > HOME_IP.60202: Flags [P.], cksum 0xceb0 (incorrect -> 0xfa82), seq 729:1054, ack 88, win 32, options [nop,nop,TS val 3236840413 ecr 22239017], length 325
12:08:02.441024 IP (tos 0x0, ttl 53, id 32608, offset 0, flags [DF], proto TCP (6), length 83)
HOME_IP.59796 > SERVER_IP.32400: Flags [P.], cksum 0xedcc (correct), seq 1561:1592, ack 61250, win 660, options [nop,nop,TS val 1397736 ecr 3236840402], length 31
12:08:02.441061 IP (tos 0x0, ttl 64, id 41192, offset 0, flags [DF], proto TCP (6), length 52)
SERVER_IP.32400 > HOME_IP.59796: Flags [.], cksum 0xcd6b (incorrect -> 0x2330), ack 1592, win 32, options [nop,nop,TS val 3236840414 ecr 1397736], length 0
12:08:02.441215 IP (tos 0x0, ttl 64, id 41193, offset 0, flags [DF], proto TCP (6), length 52)
SERVER_IP.32400 > HOME_IP.59796: Flags [F.], cksum 0xcd6b (incorrect -> 0x232f), seq 61250, ack 1592, win 32, options [nop,nop,TS val 3236840414 ecr 1397736], length 0
12:08:02.444571 IP (tos 0x0, ttl 53, id 32609, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59796 > SERVER_IP.32400: Flags [R.], cksum 0x1fe3 (correct), seq 1592, ack 61250, win 885, options [nop,nop,TS val 1397736 ecr 3236840402], length 0
12:08:02.446246 IP (tos 0x0, ttl 53, id 23728, offset 0, flags [DF], proto TCP (6), length 60)
HOME_IP.59798 > SERVER_IP.32400: Flags [S], cksum 0x5133 (correct), seq 620891993, win 14600, options [mss 1460,sackOK,TS val 1397737 ecr 0,nop,wscale 6], length 0
12:08:02.446338 IP (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto TCP (6), length 60)
SERVER_IP.32400 > HOME_IP.59798: Flags [S.], cksum 0xcd73 (incorrect -> 0xb4f8), seq 3963908859, ack 620891994, win 28960, options [mss 1460,sackOK,TS val 3236840414 ecr 1397737,nop,wscale 10], length 0
12:08:02.454698 IP (tos 0x0, ttl 53, id 49297, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.60202 > SERVER_IP.32400: Flags [.], cksum 0x7d55 (correct), ack 1054, win 218, options [nop,nop,TS val 22239024 ecr 3236840413], length 0
12:08:02.466275 IP (tos 0x0, ttl 53, id 12891, offset 0, flags [DF], proto TCP (6), length 40)
HOME_IP.59796 > SERVER_IP.32400: Flags [R], cksum 0x49e3 (correct), seq 4258542270, win 0, length 0
12:08:02.466307 IP (tos 0x0, ttl 53, id 12892, offset 0, flags [DF], proto TCP (6), length 40)
HOME_IP.59796 > SERVER_IP.32400: Flags [R], cksum 0x49e3 (correct), seq 4258542270, win 0, length 0
12:08:02.469819 IP (tos 0x0, ttl 53, id 23729, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59798 > SERVER_IP.32400: Flags [.], cksum 0x5401 (correct), ack 1, win 229, options [nop,nop,TS val 1397739 ecr 3236840414], length 0
12:08:02.469879 IP (tos 0x0, ttl 53, id 23730, offset 0, flags [DF], proto TCP (6), length 575)
HOME_IP.59798 > SERVER_IP.32400: Flags [P.], cksum 0x5aa9 (correct), seq 1:524, ack 1, win 229, options [nop,nop,TS val 1397739 ecr 3236840414], length 523
12:08:02.469932 IP (tos 0x0, ttl 64, id 12573, offset 0, flags [DF], proto TCP (6), length 52)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xcd6b (incorrect -> 0x52ba), ack 524, win 30, options [nop,nop,TS val 3236840417 ecr 1397739], length 0
12:08:02.499025 IP (tos 0x0, ttl 64, id 12574, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0xc11c), seq 1:1449, ack 524, win 30, options [nop,nop,TS val 3236840419 ecr 1397739], length 1448
12:08:02.499038 IP (tos 0x0, ttl 64, id 12575, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0xffeb), seq 1449:2897, ack 524, win 30, options [nop,nop,TS val 3236840419 ecr 1397739], length 1448
12:08:02.499078 IP (tos 0x0, ttl 64, id 12576, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0xf146), seq 2897:4345, ack 524, win 30, options [nop,nop,TS val 3236840420 ecr 1397739], length 1448
12:08:02.499085 IP (tos 0x0, ttl 64, id 12577, offset 0, flags [DF], proto TCP (6), length 763)
SERVER_IP.32400 > HOME_IP.59798: Flags [P.], cksum 0xd032 (incorrect -> 0x75d5), seq 4345:5056, ack 524, win 30, options [nop,nop,TS val 3236840420 ecr 1397739], length 711
12:08:02.521870 IP (tos 0x0, ttl 53, id 23731, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59798 > SERVER_IP.32400: Flags [.], cksum 0x4c17 (correct), ack 1449, win 274, options [nop,nop,TS val 1397744 ecr 3236840419], length 0
12:08:02.521917 IP (tos 0x0, ttl 53, id 23732, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59798 > SERVER_IP.32400: Flags [.], cksum 0x4642 (correct), ack 2897, win 319, options [nop,nop,TS val 1397744 ecr 3236840419], length 0
12:08:02.521940 IP (tos 0x0, ttl 53, id 23733, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59798 > SERVER_IP.32400: Flags [.], cksum 0x406c (correct), ack 4345, win 364, options [nop,nop,TS val 1397744 ecr 3236840420], length 0
12:08:02.521959 IP (tos 0x0, ttl 53, id 23734, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.59798 > SERVER_IP.32400: Flags [.], cksum 0x3d77 (correct), ack 5056, win 410, options [nop,nop,TS val 1397744 ecr 3236840420], length 0
12:08:02.531015 IP (tos 0x0, ttl 53, id 23735, offset 0, flags [DF], proto TCP (6), length 127)
HOME_IP.59798 > SERVER_IP.32400: Flags [P.], cksum 0x62e2 (correct), seq 524:599, ack 5056, win 410, options [nop,nop,TS val 1397745 ecr 3236840420], length 75
12:08:02.531392 IP (tos 0x0, ttl 53, id 23736, offset 0, flags [DF], proto TCP (6), length 58)
HOME_IP.59798 > SERVER_IP.32400: Flags [P.], cksum 0x2519 (correct), seq 599:605, ack 5056, win 410, options [nop,nop,TS val 1397745 ecr 3236840420], length 6
12:08:02.531752 IP (tos 0x0, ttl 53, id 23737, offset 0, flags [DF], proto TCP (6), length 97)
HOME_IP.59798 > SERVER_IP.32400: Flags [P.], cksum 0x1852 (correct), seq 605:650, ack 5056, win 410, options [nop,nop,TS val 1397745 ecr 3236840420], length 45
12:08:02.533183 IP (tos 0x0, ttl 64, id 12578, offset 0, flags [DF], proto TCP (6), length 52)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xcd6b (incorrect -> 0x3e71), ack 650, win 30, options [nop,nop,TS val 3236840423 ecr 1397745], length 0
12:08:02.533839 IP (tos 0x0, ttl 64, id 12579, offset 0, flags [DF], proto TCP (6), length 103)
SERVER_IP.32400 > HOME_IP.59798: Flags [P.], cksum 0xcd9e (incorrect -> 0xc49f), seq 5056:5107, ack 650, win 30, options [nop,nop,TS val 3236840423 ecr 1397745], length 51
12:08:02.558714 IP (tos 0x0, ttl 53, id 23738, offset 0, flags [DF], proto TCP (6), length 968)
HOME_IP.59798 > SERVER_IP.32400: Flags [P.], cksum 0x18ec (correct), seq 650:1566, ack 5107, win 410, options [nop,nop,TS val 1397748 ecr 3236840423], length 916
12:08:02.573968 IP (tos 0x0, ttl 64, id 12580, offset 0, flags [DF], proto TCP (6), length 426)
SERVER_IP.32400 > HOME_IP.59798: Flags [P.], cksum 0xcee1 (incorrect -> 0x8fa8), seq 5107:5481, ack 1566, win 32, options [nop,nop,TS val 3236840427 ecr 1397748], length 374
12:08:02.575235 IP (tos 0x0, ttl 64, id 12581, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0x4f0f), seq 5481:6929, ack 1566, win 32, options [nop,nop,TS val 3236840427 ecr 1397748], length 1448
12:08:02.575245 IP (tos 0x0, ttl 64, id 12582, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0xa9f1), seq 6929:8377, ack 1566, win 32, options [nop,nop,TS val 3236840427 ecr 1397748], length 1448
12:08:02.575290 IP (tos 0x0, ttl 64, id 12583, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0x90a1), seq 8377:9825, ack 1566, win 32, options [nop,nop,TS val 3236840427 ecr 1397748], length 1448
12:08:02.575297 IP (tos 0x0, ttl 64, id 12584, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0xd772), seq 9825:11273, ack 1566, win 32, options [nop,nop,TS val 3236840427 ecr 1397748], length 1448
12:08:02.582532 IP (tos 0x0, ttl 64, id 12585, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.59798: Flags [.], cksum 0xd313 (incorrect -> 0x3087), seq 11273:12721, ack 1566, win 32, options [nop,nop,TS val 3236840428 ecr 1397748], length 1448
12:08:02.582545 IP (tos 0x0, ttl 64, id 12586, offset 0, flags [DF], proto TCP (6), length 1500)
以下是通过 Android 应用程序进行流式传输时的日志
12:16:14.236701 IP (tos 0x0, ttl 64, id 28996, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xd9c9), seq 23858662:23860110, ack 1097, win 31, options [nop,nop,TS val 3236889460 ecr 22332949], length 1448
12:16:14.237959 IP (tos 0x0, ttl 53, id 51063, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0x5279 (correct), ack 23844182, win 3068, options [nop,nop,TS val 22332952 ecr 3236889458], length 0
12:16:14.245223 IP (tos 0x0, ttl 53, id 51064, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0x472c (correct), ack 23847078, win 3063, options [nop,nop,TS val 22332954 ecr 3236889458], length 0
12:16:14.246725 IP (tos 0x0, ttl 64, id 28997, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x3d90), seq 23860110:23861558, ack 1097, win 31, options [nop,nop,TS val 3236889461 ecr 22332954], length 1448
12:16:14.246735 IP (tos 0x0, ttl 64, id 28998, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xd5c0), seq 23861558:23863006, ack 1097, win 31, options [nop,nop,TS val 3236889461 ecr 22332954], length 1448
12:16:14.246762 IP (tos 0x0, ttl 64, id 28999, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xa94a), seq 23863006:23864454, ack 1097, win 31, options [nop,nop,TS val 3236889461 ecr 22332954], length 1448
12:16:14.246769 IP (tos 0x0, ttl 64, id 29000, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x9ad7), seq 23864454:23865902, ack 1097, win 31, options [nop,nop,TS val 3236889461 ecr 22332954], length 1448
12:16:14.248756 IP (tos 0x0, ttl 53, id 51065, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0x3bd5 (correct), ack 23849974, win 3068, options [nop,nop,TS val 22332955 ecr 3236889459], length 0
12:16:14.248815 IP (tos 0x0, ttl 53, id 51066, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0x2add (correct), ack 23854318, win 3068, options [nop,nop,TS val 22332955 ecr 3236889459], length 0
12:16:14.256850 IP (tos 0x0, ttl 64, id 29001, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x5da4), seq 23865902:23867350, ack 1097, win 31, options [nop,nop,TS val 3236889462 ecr 22332955], length 1448
12:16:14.256862 IP (tos 0x0, ttl 64, id 29002, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xcefe), seq 23867350:23868798, ack 1097, win 31, options [nop,nop,TS val 3236889462 ecr 22332955], length 1448
12:16:14.256896 IP (tos 0x0, ttl 64, id 29003, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xc49b), seq 23868798:23870246, ack 1097, win 31, options [nop,nop,TS val 3236889462 ecr 22332955], length 1448
12:16:14.256903 IP (tos 0x0, ttl 64, id 29004, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x216f), seq 23870246:23871694, ack 1097, win 31, options [nop,nop,TS val 3236889462 ecr 22332955], length 1448
12:16:14.257888 IP (tos 0x0, ttl 53, id 51067, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0x1439 (correct), ack 23860110, win 3068, options [nop,nop,TS val 22332958 ecr 3236889460], length 0
12:16:14.266809 IP (tos 0x0, ttl 64, id 29005, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x1377), seq 23871694:23873142, ack 1097, win 31, options [nop,nop,TS val 3236889463 ecr 22332958], length 1448
12:16:14.266821 IP (tos 0x0, ttl 64, id 29006, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x8e09), seq 23873142:23874590, ack 1097, win 31, options [nop,nop,TS val 3236889463 ecr 22332958], length 1448
12:16:14.266855 IP (tos 0x0, ttl 64, id 29007, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x1512), seq 23874590:23876038, ack 1097, win 31, options [nop,nop,TS val 3236889463 ecr 22332958], length 1448
12:16:14.266861 IP (tos 0x0, ttl 64, id 29008, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x53b5), seq 23876038:23877486, ack 1097, win 31, options [nop,nop,TS val 3236889463 ecr 22332958], length 1448
12:16:14.268871 IP (tos 0x0, ttl 53, id 51068, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0xfd9f (correct), ack 23865902, win 3057, options [nop,nop,TS val 22332961 ecr 3236889461], length 0
12:16:14.276848 IP (tos 0x0, ttl 64, id 29009, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x2c18), seq 23877486:23878934, ack 1097, win 31, options [nop,nop,TS val 3236889464 ecr 22332961], length 1448
12:16:14.276859 IP (tos 0x0, ttl 64, id 29010, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x46f8), seq 23878934:23880382, ack 1097, win 31, options [nop,nop,TS val 3236889464 ecr 22332961], length 1448
12:16:14.276891 IP (tos 0x0, ttl 64, id 29011, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x8f1b), seq 23880382:23881830, ack 1097, win 31, options [nop,nop,TS val 3236889464 ecr 22332961], length 1448
12:16:14.276897 IP (tos 0x0, ttl 64, id 29012, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x1317), seq 23881830:23883278, ack 1097, win 31, options [nop,nop,TS val 3236889464 ecr 22332961], length 1448
12:16:14.277998 IP (tos 0x0, ttl 53, id 51069, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0xf240 (correct), ack 23868798, win 3068, options [nop,nop,TS val 22332964 ecr 3236889462], length 0
12:16:14.278054 IP (tos 0x0, ttl 53, id 51070, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0xe6f0 (correct), ack 23871694, win 3068, options [nop,nop,TS val 22332964 ecr 3236889462], length 0
12:16:14.286870 IP (tos 0x0, ttl 64, id 29013, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x9a46), seq 23883278:23884726, ack 1097, win 31, options [nop,nop,TS val 3236889465 ecr 22332964], length 1448
12:16:14.286882 IP (tos 0x0, ttl 64, id 29014, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x4070), seq 23884726:23886174, ack 1097, win 31, options [nop,nop,TS val 3236889465 ecr 22332964], length 1448
12:16:14.286917 IP (tos 0x0, ttl 64, id 29015, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xa15e), seq 23886174:23887622, ack 1097, win 31, options [nop,nop,TS val 3236889465 ecr 22332964], length 1448
12:16:14.286924 IP (tos 0x0, ttl 64, id 29016, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x7bb9), seq 23887622:23889070, ack 1097, win 31, options [nop,nop,TS val 3236889465 ecr 22332964], length 1448
12:16:14.290811 IP (tos 0x0, ttl 53, id 51071, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0xd04b (correct), ack 23877486, win 3068, options [nop,nop,TS val 22332968 ecr 3236889463], length 0
12:16:14.296850 IP (tos 0x0, ttl 64, id 29017, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xdfde), seq 23889070:23890518, ack 1097, win 31, options [nop,nop,TS val 3236889466 ecr 22332968], length 1448
12:16:14.296861 IP (tos 0x0, ttl 64, id 29018, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0x0a96), seq 23890518:23891966, ack 1097, win 31, options [nop,nop,TS val 3236889466 ecr 22332968], length 1448
12:16:14.296889 IP (tos 0x0, ttl 64, id 29019, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xce97), seq 23891966:23893414, ack 1097, win 31, options [nop,nop,TS val 3236889466 ecr 22332968], length 1448
12:16:14.296896 IP (tos 0x0, ttl 64, id 29020, offset 0, flags [DF], proto TCP (6), length 1500)
SERVER_IP.32400 > HOME_IP.61313: Flags [.], cksum 0xd313 (incorrect -> 0xb825), seq 23893414:23894862, ack 1097, win 31, options [nop,nop,TS val 3236889466 ecr 22332968], length 1448
12:16:14.297114 IP (tos 0x0, ttl 53, id 51072, offset 0, flags [DF], proto TCP (6), length 52)
HOME_IP.61313 > SERVER_IP.32400: Flags [.], cksum 0xc4f8 (correct), ack 23880382, win 3068, options [nop,nop,TS val 22332970 ecr 3236889464], length 0
以下是我使用 iperf3 测试的结果
ubuntu@root ~ [1]> iperf3 -c SERVER_IP -R
Connecting to host SERVER_IP, port 5201
Reverse mode, remote host SERVER_IP is sending
[ 5] local 10.0.2.15 port 43990 connected to SERVER_IP port 5201
[ ID] Interval Transfer Bitrate
[ 5] 0.00-1.00 sec 602 KBytes 4.93 Mbits/sec
[ 5] 1.00-2.00 sec 570 KBytes 4.67 Mbits/sec
[ 5] 2.00-3.00 sec 565 KBytes 4.63 Mbits/sec
[ 5] 3.00-4.00 sec 576 KBytes 4.72 Mbits/sec
[ 5] 4.00-5.00 sec 565 KBytes 4.62 Mbits/sec
[ 5] 5.00-6.00 sec 576 KBytes 4.72 Mbits/sec
[ 5] 6.00-7.00 sec 565 KBytes 4.62 Mbits/sec
[ 5] 7.00-8.00 sec 570 KBytes 4.67 Mbits/sec
[ 5] 8.00-9.00 sec 570 KBytes 4.67 Mbits/sec
[ 5] 9.00-10.00 sec 566 KBytes 4.64 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.04 sec 27.5 MBytes 23.0 Mbits/sec 0 sender
[ 5] 0.00-10.00 sec 5.59 MBytes 4.69 Mbits/sec receiver
以下是多线程的结果：
[SUM] 0.00-10.03 sec 160 MBytes 134 Mbits/sec 271 sender
[SUM] 0.00-10.00 sec 140 MBytes 118 Mbits/sec receiver
您知道是什么原因导致我出现此问题吗？我知道我当前的内核不支持 I/O 统计，或许还有其他原因。