Ethernet Buffer issue.

[SArma]

I need some help. I'm using the STM32F46 with the PHI(LAN8742A) to communicate with Android's Tablet using LWIP. The communication works great, but after sent some data from the tablet to the MCU, the communication collapse. If I increase the size of the "PBUF_POOL_BUF_SIZE" I can receive more data on the MCU but after a while, the problem starts again.