this istruction give to me a "Segmentation fault": $data(0) attach-agent $tr(S,0,0)
where $data(0) has been just defined as FTP application and $tr(S,0,0) is a TCP Module provided by ns miracle Note that the same scheme has been used in the sample "dei80211mr_infrastruct_plus_wired_tcp.tcl" in the sample directory of nsmiracle I don't know which is the problem and i've sent this mail to both the ML cheers Davide