ns2.35中扩展ns2voip++,运行voip.tcl实例报错，什么原因？

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补充：扩展框架是在该网站下载的http://cng1.iet.unipi.it/wiki/index.php/Ns2voip++，按照步骤安装到了ns2.35中，但是报以上错误，我是新手，求指导。

再补充，这是下载patch中关于init部分的代码，急求大神指点！！
proc init {} {

global opt defaultRNG ns simtime +
# create the simulator instance
set ns [new Simulator] ;# create a new simulator instance
$defaultRNG seed 1 +
# initialize statistics collection
$ns run-identifier $opt(run)
$ns stat file "$opt(out)"
$ns at $opt(warm) "$ns stat on"
$ns at $opt(duration) "finish" +
# add default probes
$ns stat add e2e_owd_a avg discrete
$ns stat add e2e_tpt avg rate
$ns stat add e2e_owpl avg rate
#$ns stat add tcp_cwnd_a avg continuous
#$ns stat add tcp_dupacks avg continuous
#$ns stat add tcp_ssthresh avg continuous
#$ns stat add tcp_rtt avg continuous
#$ns stat add tcp_srtt avg continuous +
#$ns stat add tcp_cwnd_d dst continuous 0 128 128
$ns stat add e2e_owd_d dst discrete 0.0 1.0 1000
#$ns stat add e2e_ipdv_d dst discrete 0.0 5.0 100 +
$ns stat add voip_state_duration avg discrete
$ns stat add voip_frames_recv avg counter
$ns stat add voip_frames_sent avg counter
$ns stat add voip_cell_outage avg discrete
$ns stat add voip_mos_conversation avg discrete
$ns stat add voip_playout_talkspurt_delay avg discrete
$ns stat add voip_playout_talkspurt_per avg discrete
$ns stat add voip_satisfaction avg discrete
$ns stat add voip_cell_satisfaction avg discrete
$ns stat add voip_talkspurt_duration avg discrete
$ns stat add voip_silence_duration avg discrete
$ns stat add voip_dur_fid_silence avg discrete
+
# open trace files
set opt(trace) [open "/dev/null" w] +
set simtime [clock seconds] +
$ns trace-all $opt(trace)