[ndnSIM] Questions about ConsumerWindow

Matteo Virgilio matteo.virgilio at polito.it
Thu Jun 20 01:37:08 PDT 2013

Hi All,
I'm working on ndnSim and I have some questions about the 
ConsumerWindow. I'm somewhat unclear about the retransmissions 
management. It seems that the value used for the retransmission timeout 
is not the one used for the interest lifetime value, in fact in 
CheckRetxTimeout() only the rtt is considered (or an estimation of it). 
So, when this timeout occurs, a new interest packet (for the same name) 
is scheduled for retransmission. Is this right?
If yes, I have another question, let's assume the following (simple) 
and we assume the clients is using 4s as interest lifetime. The client 
sends out one interest but the response doesn't arrive (for any reason). 
If the client retransmits the interest on a RTT basis (RTT could be very 
small with respect to the lifetime), it will see its interest discarded 
by the router because the router already has an (alive) entry for that 
name. So this kind of retransmission is useless. This lead to my final 
question: how is exactly managed the retransmission in consumerWindow 
implementation? What I'm missing?
Thanks in advance.
Best regards.


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