Depending on what you have for systems, you may or may not, need a crossover line. The TiBooks sense what you are trying to do and make the switch on their own. I do not believe that any of the other systems do this as well. If you have some cat 5 lines, see if connecting the two systems together (set one with filesharing active) and see if you can connect to it. If you cannot, then you will need a crossover line. It is far easier to just use the ethernet then to try and use the firewire connection. With the ethernet connection, you will be able to move the ~12GBs in not a lot of time (most likely under 30 minutes for a full file transfer).