ndnSIM

By default Producer application sets the freshness of all generated Data packets to ZERO. Althgouh in the application layer zero is interpreted to infinity, this causes unexpected behavior at NFD layer, in CS replacement policy.
By running a simple scenario in ndnSIM (where there is one consumer, one producer, and one node in the middle), and enabling the log component for Priority Fifo Cache replacement policy we can see an output like below:

As is shown, replacement policy moves Data packets from FIFO queue to STALE queue, immediately, because it does not understand the meaning of zero freshness.
Accordingly, we can fix this problem by changing the default value of Data packets. But the question would be what should be the default freshness.
The second solution would be changing the NFD layer.