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 GÉANT2 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

-- TobyRodwell - 25 Jun 2006
Topic revision: r1 - 2006-06-25 - TobyRodwell
 
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