Hello, can someone help with TCP problem? I'm trying to run following tcl code: or {set i 1} {$i<=$NetNb1} { incr i } { for {set j 1} {$j<=$NumFlows} { incr j } { set tcpsrc($i,$j) [new Agent/TCP/Newreno] set tcp_snk($i,$j) [new Agent/TCPSink/DelAck] $tcpsrc($i,$j) set packetsize_ 1000 $ns attach-agent $N1($i) tcpsrc($i,$j) $ns attach-agent $Server tcp_snk($i,$j) $ns connect $tcpsrc($i,$j) $tcp_snk($i,$j) set ftp($i,$j) [$tcpsrc($i,$j) attach-source FTP] } } ....a so on, but instead proper function I get the error output like this: invalid command name "tcpsrc(1,1)" while executing "$agent set node_ $self" (procedure "_o58" line 4) (Node attach line 4) invoked from within "$node attach $agent" (procedure "_o3" line 2) (Simulator attach-agent line 2) invoked from within "$ns attach-agent $N1($i) tcpsrc($i,$j! ) " ("for" body line 8) invoked from within "for {set i 1} {$i<=$NetNb1} { incr i } { for {set j 1} {$j<=$NumFlows} { incr j } { set tcpsrc($i,$j) [new Agent/TCP/Newreno] # setting tcpsink w..." (file "mojepareto.tcl" line 54) The whole part of code is similar to 'NS2 for beginners' (Chapter 4-TCP/IP description and simulation), is it possible, that it's wrong? Thank You for help.