Hi all I have installed patch Mac/802_11e successfully in ns-2.34. When i run tcl script (multi_udpflows) which is present in the patch. The following error occur. moazzam@moazzam-OptiPlex-GX270:~$ cd /home/moazzam/mb moazzam@moazzam-OptiPlex-GX270:~/mb$ ns multi_udpflows.tcl num_nodes is set 5 wired node 0 created wired node 1 created wired node 2 created invalid command name "Mac/802_11e" while executing "Mac/802_11e create _o54 " invoked from within "catch "$className create $o $args" msg" invoked from within "if [catch "$className create $o $args" msg] { if [string match "__FAILED_SHADOW_OBJECT_" $msg] { delete $o return "" } global errorInfo error "class $..." (procedure "new" line 3) invoked from within "new $mactype" (procedure "_o44" line 10) (Node/MobileNode add-interface line 10) invoked from within "$node add-interface $chan $propInstance_ $llType_ $macType_ $ifqType_ $ifqlen_ $phyType_ $antType_ $topoInstance_ $inerrProc_ $outerrProc_ $FECProc_" (procedure "_o3" line 83) (Simulator create-wireless-node line 83) invoked from within "_o3 create-wireless-node 1.0.0" ("eval" body line 1) invoked from within "eval $self create-wireless-node $args" (procedure "_o3" line 23) (Simulator node line 23) invoked from within "$ns node 1.0.0" invoked from within "set BS(0) [$ns node 1.0.0]" (file "multi_udpflows.tcl" line 92) moazzam@moazzam-OptiPlex-GX270:~/mb$ Regards Moazzam