Questions about programming the NIOS CPU

I'm not sure if this should be in this forum, or in the general forum, but I'll put it here, since most of my questions are software related.

Some background on my project:

This is being done for a 4th year design project in Electrical Engineering, and this is my first experience with any kind of high end (mor ethan 8051) embedded system programming. I'm using a Stratix Professional Edition (Stratix 1S40 FPGA) dev kit, with Quartus II Version 4.0 and NIOS version 3.10 (that's the versions of the software that my supervisor had available, unfortunately I can't use the newer version of NIOS with this version of Quartus II).

The project involves sending streaming video over Ethernet. Fortunately, I don't have to do any of the video processing on chip, all that I am doing is processing data that is coming out of a compression chip. So, I have a 32-bit parallel (I was thinking I would probably use one of the Proto2 40 pin busses) that will continuously be sending me data, and I must forward that data to the other development board over TCP/IP on Ethernet, which then sends it back out in real time to the decompression ASIC.

My problem is that I'm not sure what the best way to approach this would be. I was thinking I should take the incoming data and buffer it in memory, then send it out (not sure if I should do this in DMA or let the CPU handle it all in software. Will I run into performance issues if I do it in software? I am likely going to need ~30Mbit/second of throughput on the ethernet port). How exactly should I handle the buffering, and how do I create a circular style buffer that over-writes itself with new data (once that data has been transmitted (and TCP ACK received, something that plugs handles for me) it can be deleted). Can I create the kind of buffer that I want by using the DMA features?

I'm currently at the point that I've gone through all the included NIOS tutorials, and I've made the example PLUGS programs run, as well as modifying them slightly, but I'm not sure where to proceed from here. I've begun to write the program I need to use on the receiver side, but I'm stuck with this whole buffering issue.

Sorry if these are bad questions to be asking, if there are some ressources that I&#39;ve missed reading about it, please let me know. Any help I can get will be much appreciated http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/smile.gif .