Can't stop ftp transfer

[=?ks_c_5601-1987?B?s6q9wrG4?= <sgna@dokdo.dongguk.ac.kr>]

Hi  ns users,

I'm tried to stop a ftp transfer in NS 2.1b3  at given time as follows.

$ns at 0.0 $ftp start
$ns at 20.0 $ftp stop

But the source just goes on sending.
Why this happened?

Please let me know the solution.
Thanks.

 

- SeungGu Na -