Hi Bala,
Please check the following from the readme file, I hope this helps.
To experiment with the receive throughput, try to increase the number of receive buffers.
For LPC platforms, where zero-copy on receive is implemented, the number of buffers is determined by ENET_RXBD_NUM definition.
When using ENET QOS, where zero-copy on receive is not implemented, increase the PBUF_POOL_SIZE in the file lwipopts.h or on command line.
For other platforms, where zero-copy on receive is implemented, it is determined by ENET_RXBUFF_NUM definition.
Also increase the TCP receive window by changing TCP_WND definition in the file lwipopts.h or on command line.
Make sure that TCP_WND is not larger than (number of receive buffers / TCP_MSS).
For RTOS applications, DEFAULT_THREAD_PRIO and TCPIP_THREAD_PRIO values can have effect on maximum throughput as well.
Best regards,
Felipe