How to change pointopoint link datarate during run time in NS3

Question

I'm new to NS3. I have a query in changing the pointtopoint link datarate during the runtime. I tried a solution which is mentioned in https://stackoverflow.com/a/65514090/13121848 . But here SetDeviceAttribute is not resolved for me.

void
ModifyLinkRate(PointToPointNetDevice *dev) {
   dev->SetDeviceAttribute("DataRate", StringValue ("1Mbps"));
   //dev->SetAttribute("DataRate", StringValue ("1Mbps"));
}
int
main (int argc, char *argv[])
{
...
   PointToPointHelper pointToPoint;
   pointToPoint.SetDeviceAttribute ("DataRate", StringValue (linkRate));
...
   Simulator::Schedule(Seconds(2.0), &ModifyLinkRate, &pointToPoint );
}

Answer 1

Inorder to change the datarate of a pointTopoint link, the PointToPointNetDevice installed in a node has to be retrieved. This can be done using the NetDeviceContainer where the node is associated. The example code is below,

void
ModifyLinkRate(NetDeviceContainer *ptp, DataRate lr) {
    StaticCast<PointToPointNetDevice>(ptp->Get(0))->SetDataRate(lr);
}
int
main (int argc, char *argv[])
{
...
   PointToPointHelper pointToPoint;
   pointToPoint.SetDeviceAttribute ("DataRate", StringValue (linkRate));
...
   NetDeviceContainer p2pDevices = pointToPoint.Install (p2pNodes);
...
    Simulator::Schedule(Seconds(2.0), &ModifyLinkRate, &p2pDevices,DataRate("20Mbps"));
}