Hello all,
I'm using the XilNet library on a Virtex-II Pro (PPC), and my objective is to send quite large amounts of data via an external MAC/PHY (SMSC
91c111) to a computer running Windows XP. The server application on the PPC is quite simple, it waits for the client to connect and then it starts streaming the data as fast as the PC is able to receive it. The protocol used is TCP.
The throughput is very poor, about 800 kbps at the moment. And I can't really figure out why. Using Ethereal I have seen that it takes about 15 ms for the PC to acknowledge the data packages from the FPGA, while the ACKs from the FPGA is sent much quicker. Every once in a while, though, the ACK is sent directly after received data packet.
Has anyone seen similar symptoms with XilNet? Should I swap to LwIP instead? How much work (approximately) is needed to port LwIP to work with an external MAC/PHY chip? Not very surprisingly Xilinx only provide ports to theirs own MAC IPs. The reason I used XilNet in the first place is that I'm in a bit of time shortage... Also, I have no external memory, would it be possible to run XMK and LwIP from BRAM on a Virtex-II Pro-40?