Trace Source is getting disconnected

[ofri...@annapurnalabs.com]

Hi,

I'm using TraceConnectWithoutContext to log the RTT of an ack packet - in TcpSocketBase

socket->TraceConnectWithoutContext ("RTT", MakeCallback (&Application::SomeFunc, this));

void SomeFunc (Time oldVal, Time newVal){
  NS_LOG_UNCOND("the packet rtt is: " << newVal);
}

topology - I have 2 nodes connected to a third node, all connections are p2p with data rate of 10Gbps

I'm sending TCP transportation from one end node the the second one (not the third one) in a the same rate (10Gbps), and in the first ~15ms the callback is being called, and then suddenly it stops.

when I'm sending TCP transportation in a smaller rate it doesn't happen

I tried putting breakpoint at ObjectBase::TraceDisconnectWithoutContext, but it never gets there.

Any idea why this is happening? 

Thanks,

Ofri

[Konstantinos]

Hi,

Are you sure that the trace is disconnected or could it be that the RTT does not change?

If there is no change in the estimated RTT, then your callback would not be called.

Regards,

K.

[ofri...@annapurnalabs.com]

OK, you are right, when the traffic is in the same rate as the link the lastRtt gets to a certain value and never change after that.

First of all, thank you, for some reason I assumed that won't happen.

I think the easiest way to log the rtt of an ack packet would still be to use the RTT tracing, just in case the lastRtt doesn't change, I'll add 1ns to it.