I try to figure out why LWIP drops packets when small packets are
received in high rate.
On debugging the issue, I see that after it search for a matching pcb,
it results in pcb null, and then packets are dropped.
What does it mean ? Does it mean there are no free PCB ? I tried to increase
MEMP_NUM_UDP_PCB from 10, to 200, but there is no change in behavior.
I also searched for an API which gives count of free pcb, but found none.
Is there any idea why it happens and how to deal with it ?