error while executing

[sai-kumar2413]

i am getting an error while executing the code ns3.39

aborted. cond="ndi->second.m_rootQueueDisc", msg="Cannot install a root queue disc on a device already having one. Delete the existing queue disc first.", +0.000000000s -1 file=/home/sai/ns-allinone-3.39/ns-3.39/src/traffic-control/model/traffic-control-layer.cc, line=233
NS_FATAL, terminating
terminate called without an active exception
Command 'build/scratch/ns3.39-source-code-default' died with <Signals.SIGABRT: 6>.

can resolve it?

[maahmed24712]

I went to the ‘ns-3.29/src/traffic-control/model’ directory and opened the ‘traffic-control-layer.cc’ file. I commented out lines 209-211, which then allowed me to change the existing ‘DropTail’ queue to a FIFO queue.

[Kikashii]

which lines did you comment? Can you paste them here?

[Superdog-ccr]

U can try to uninstall the existing queue before install a root queue and it will work:

TrafficControlHelper tch;
tch.Uninstall(devices);
tch.SetRootQueueDisc("ns3::FifoQueueDisc");
tch.Install(devices);