Example Result of BWCTL/SS Script
The command './testtcptest.sh mp1.gen.ch.geant2.net 20 0.2' was run on mp1.fra.de.geant2.net, a G�ANT2 Measurement Point device, on 25 Jun 2006, 21:15:58 local time (060625211558). It generated two result files; tcp_test-060625211558-pm1.fra.de.geant2.net.results and stat_changes-060625211558-pm1.fra.de.geant2.net.results
TCP Result
This file is made up of three parts: the Bwctl results, a ping test and the 'ss' results (which show cwnd and ssthresh values every 0.2s (in this case). Note that ssthresh is actually '100' until the first congestion event. After that, it changes (to 1449) and then every subsequent change indicates anothe rcongestion event (in this case almost certainly packet loss). Because of the short RTT (8ms, as per the ping result) the test still managed to run at over 900Mbps.
060625211558 RECEIVER START 3360251762.168253: iperf -B 62.40.122.2 -P 1 -s -f b -m -p 5001 -t 20 -i 2 ------------------------------------------------------------ Server listening on TCP port 5001 Binding to local address 62.40.122.2 TCP window size: 12000000 Byte (default) ------------------------------------------------------------ [ 14] local 62.40.122.2 port 5001 connected with 62.40.122.10 port 5001 [ 14] 0.0- 2.0 sec 198457088 Bytes 793828352 bits/sec [ 14] 2.0- 4.0 sec 198209480 Bytes 792837920 bits/sec [ 14] 4.0- 6.0 sec 190384488 Bytes 761537952 bits/sec [ 14] 6.0- 8.0 sec 205028112 Bytes 820112448 bits/sec [ 14] 8.0-10.0 sec 233463936 Bytes 933855744 bits/sec [ 14] 10.0-12.0 sec 233691272 Bytes 934765088 bits/sec [ 14] 12.0-14.0 sec 234703424 Bytes 938813696 bits/sec [ 14] 14.0-16.0 sec 233673400 Bytes 934693600 bits/sec [ 14] 16.0-18.0 sec 234047976 Bytes 936191904 bits/sec [ 14] 18.0-20.0 sec 234337080 Bytes 937348320 bits/sec [ 14] 0.0-20.1 sec 2203090944 Bytes 878583539 bits/sec [ 14] MSS size 1448 bytes (MTU 1500 bytes, ethernet) RECEIVER END PING fe0-vlan71.srv3.gen.ch.geant2.net (62.40.122.2) 56(84) bytes of data. 64 bytes from fe0-vlan71.srv3.gen.ch.geant2.net (62.40.122.2): icmp_seq=0 ttl=62 time=8.35 ms 64 bytes from fe0-vlan71.srv3.gen.ch.geant2.net (62.40.122.2): icmp_seq=1 ttl=62 time=8.34 ms 64 bytes from fe0-vlan71.srv3.gen.ch.geant2.net (62.40.122.2): icmp_seq=2 ttl=62 time=8.40 ms --- fe0-vlan71.srv3.gen.ch.geant2.net ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2010ms rtt min/avg/max/mdev = 8.343/8.366/8.402/0.078 ms, pipe 2 4.8 ESTAB 0 6007752 62.40.122.10:5001 62.40.122.2:5001 rto:0.208 cwnd:683 ssthresh:100 5.0 ESTAB 0 6825872 62.40.122.10:5001 62.40.122.2:5001 rto:0.216 cwnd:1525 ssthresh:100 5.2 ESTAB 0 6552024 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:1641 ssthresh:1449 5.4 ESTAB 0 8580920 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:1423 ssthresh:1423 5.6 ESTAB 0 8732888 62.40.122.10:5001 62.40.122.2:5001 rto:0.244 cwnd:1555 ssthresh:1423 5.8 ESTAB 0 7486408 62.40.122.10:5001 62.40.122.2:5001 rto:0.232 cwnd:1594 ssthresh:1423 6.0 ESTAB 0 6067120 62.40.122.10:5001 62.40.122.2:5001 rto:0.252 cwnd:1349 ssthresh:1275 6.2 ESTAB 0 7635304 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1428 ssthresh:1275 6.4 ESTAB 0 6896824 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1431 ssthresh:1275 6.6 ESTAB 0 6447944 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1433 ssthresh:1275 6.8 ESTAB 0 6173536 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1436 ssthresh:1275 7.0 ESTAB 0 6862128 62.40.122.10:5001 62.40.122.2:5001 rto:0.232 cwnd:1150 ssthresh:1150 7.2 ESTAB 0 7615032 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1402 ssthresh:1150 7.4 ESTAB 0 7219552 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1144 ssthresh:1144 7.6 ESTAB 0 8790808 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1264 ssthresh:1144 7.8 ESTAB 0 7339912 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:1281 ssthresh:1144 8.0 ESTAB 0 6686864 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:1128 ssthresh:1025 8.2 ESTAB 0 7633856 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:737 ssthresh:918 8.4 ESTAB 0 7342808 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:1029 ssthresh:1025 8.6 ESTAB 0 7981488 62.40.122.10:5001 62.40.122.2:5001 rto:0.228 cwnd:775 ssthresh:824 8.8 ESTAB 0 5996168 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:920 ssthresh:824 9.0 ESTAB 0 5950192 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:923 ssthresh:824 9.2 ESTAB 0 7761280 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:779 ssthresh:740 9.4 ESTAB 0 6610120 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:828 ssthresh:740 9.6 ESTAB 0 6126904 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:833 ssthresh:740 9.8 ESTAB 0 7807616 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:746 ssthresh:668 10.0 ESTAB 0 6960536 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:831 ssthresh:668 10.2 ESTAB 0 5944040 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:835 ssthresh:668 10.4 ESTAB 0 6720608 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:840 ssthresh:668 10.6 ESTAB 0 7612136 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:622 ssthresh:671 10.8 ESTAB 0 7752320 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:834 ssthresh:671 11.0 ESTAB 0 8501208 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:620 ssthresh:669 11.2 ESTAB 0 8860312 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:747 ssthresh:669 11.4 ESTAB 0 7357288 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:752 ssthresh:669 11.6 ESTAB 0 6509344 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:756 ssthresh:669 11.8 ESTAB 0 8525824 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 12.0 ESTAB 0 7510776 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:757 ssthresh:669 12.2 ESTAB 0 6314728 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 12.4 ESTAB 0 8175408 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 12.6 ESTAB 0 7649784 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 12.8 ESTAB 0 6140968 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 13.0 ESTAB 0 7771416 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 13.2 ESTAB 0 6763608 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 13.4 ESTAB 0 6441240 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 13.6 ESTAB 0 7230312 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 13.8 ESTAB 0 8423368 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 14.0 ESTAB 0 7444168 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 14.2 ESTAB 0 6375288 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:757 ssthresh:669 14.4 ESTAB 0 8371032 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 14.6 ESTAB 0 7626616 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 14.8 ESTAB 0 6277080 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:757 ssthresh:669 15.0 ESTAB 0 7554536 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 15.2 ESTAB 0 8282632 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 15.4 ESTAB 0 7444168 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 15.6 ESTAB 0 6047336 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 15.8 ESTAB 0 7663912 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 16.0 ESTAB 0 8612704 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 16.2 ESTAB 0 7473128 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 16.4 ESTAB 0 6057336 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 16.6 ESTAB 0 7249672 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 16.8 ESTAB 0 7596208 62.40.122.10:5001 62.40.122.2:5001 rto:0.224 cwnd:757 ssthresh:669 17.0 ESTAB 0 8217160 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 17.2 ESTAB 0 8838184 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 17.4 ESTAB 0 6760712 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 17.6 ESTAB 0 6716776 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 17.8 ESTAB 0 8697128 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 18.0 ESTAB 0 8446184 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 18.2 ESTAB 0 7195112 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 18.4 ESTAB 0 6849040 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 18.6 ESTAB 0 7929224 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 18.8 ESTAB 0 8053776 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 19.0 ESTAB 0 8243464 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 19.2 ESTAB 0 8615544 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 19.4 ESTAB 0 7432584 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 19.6 ESTAB 0 6233640 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 19.8 ESTAB 0 6757864 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 20.0 ESTAB 0 6917080 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 20.2 ESTAB 0 6906568 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 20.4 ESTAB 0 7193624 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 20.6 ESTAB 0 7782376 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 20.8 ESTAB 0 8056672 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 21.0 ESTAB 0 8446184 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 21.2 ESTAB 0 8382472 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 21.4 ESTAB 0 6740440 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 21.6 ESTAB 0 5967880 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 21.8 ESTAB 0 8108448 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669 22.0 FIN-WAIT-1 0 6779025 62.40.122.10:5001 62.40.122.2:5001 rto:0.22 cwnd:757 ssthresh:669
Netstat Difference
This file shows the difference in 'netasts -s' (netstat statisistics) run immediately before and after the test. Note the number of TCP losses and retransmissions. On a larget BDP path this would casue serious problems.
2c2 < 4028590310 total packets received --- > 4029359442 total packets received 5,6c5,6 < 4028566093 incoming packets delivered < 424521728 requests sent out --- > 4029335225 incoming packets delivered > 426044288 requests sent out 20c20 < 1816196 ICMP messages sent --- > 1816221 ICMP messages sent 23c23 < destination unreachable: 1814985 --- > destination unreachable: 1815010 26,27c26,27 < 22738 active connections openings < 17611 passive connection openings --- > 22742 active connections openings > 17612 passive connection openings 31,33c31,33 < 3953422230 segments received < 321952583 segments send out < 4030754 segments retransmited --- > 3954191012 segments received > 323474647 segments send out > 4031256 segments retransmited 37,38c37,38 < 63481111 packets received < 1814750 packets to unknown port received. --- > 63481436 packets received > 1814775 packets to unknown port received. 40c40 < 101280859 packets sent --- > 101281338 packets sent 47c47 < 83670 delayed acks sent --- > 83676 delayed acks sent 53c53 < 2148653238 packets header predicted --- > 2148653260 packets header predicted 55,56c55,56 < TCPPureAcks: 57876113 < TCPHPAcks: 1509636499 --- > TCPPureAcks: 57894124 > TCPHPAcks: 1510387226 58c58 < TCPSackRecovery: 32225 --- > TCPSackRecovery: 32236 63,65c63,65 < TCPTSReorder: 24200 < TCPFullUndo: 3930 < TCPPartialUndo: 2320852 --- > TCPTSReorder: 24201 > TCPFullUndo: 3931 > TCPPartialUndo: 2321482 68c68 < TCPLoss: 4960090 --- > TCPLoss: 4963523 73c73 < TCPFastRetrans: 2700486 --- > TCPFastRetrans: 2700988 83c83 < TCPDSACKRecv: 2818234 --- > TCPDSACKRecv: 2818236
-- Main.TobyRodwell - 25 Jun 2006