NDT-DEV email list created

Status: New
Owner: ----
Labels: Type-Defect Severity-Medium

New issue 49 by sekharnv73: RTT reported is not matching with the RTT  
reported through ping command.
http://code.google.com/p/ndt/issues/detail?id=49

What steps will reproduce the problem?

1. Connect server and client in a 1GBit Switch
2. Start both servers (fakewww and web100)
3. Set the following tcp paramters in client.
        echo 1 > /proc/sys/net/ipv4/tcp_moderate_rcvbuf
        echo 4194304 > /proc/sys/net/core/wmem_max
        echo 4194304 > /proc/sys/net/core/rmem_max
        echo "4096 87380 4194304" > /proc/sys/net/ipv4/tcp_rmem
        echo "4096 16384 4194304" > /proc/sys/net/ipv4/tcp_wmem
        echo "1" > /proc/sys/net/ipv4/tcp_timestamps
        echo "1" > /proc/sys/net/ipv4/tcp_window_scaling
        echo "1" > /proc/sys/net/ipv4/tcp_sack
        echo "0" > /proc/sys/net/ipv4/tcp_ecn

4. Click the start button to start the test and wait till client complete
the test.
5. Check the RTT reported in the statistics window.

What is the expected output? What do you see instead?
RTT displayed in the statistics window should be matched with the RTT  
showed by the ping command but RTT displayed by the NDT is more.




What version of the product are you using? On what operating system?
NDT server 3.6.3
Client : Linux (Ubuntu 9)


Please use labels and text to provide additional information.


Attachments:
        RTT_problem.png  182 KB
        RTT_ping.png  290 KB