Networking Two Computers via USB

[Bernd Walter]

On Thu, Dec 30, 2004 at 10:36:07PM -0800, Douglas Allen wrote:
> Hi hackers,
>  
>    I am interested in connecting my Linux machine to my windows XP machine.


Neither Linux nor Windows is FreeBSD, why do you ask in a FreeBSD
list?

 
>    I was going to try the USB ports first. Now I've opened a can of worms.
>  
>    Assuming one could buy a USB A-male to A-male cable, is there a danger in connecting 
>  
>    each computer directly? Where can I get more information on the pin outs of the USB ports?
>  
>    I see that adaptors are sold for such purposes. Is that because there is some danger of
>  
>    frying those ports? I know there is a power connection on a USB port. I don't need to supply 
>  
>    power to any PC port. What leads may I use just for data? Do they need to be like a null-
>  
>    modem cable? Probably that's why there are so many schemes to xfer data such as flash
>  
>    memory keys. I want to go direct without a hub or an adaptor. Is there a cable to make it
>  
>    all work ok? Any reply would be greatly welcome. 73s all.

USB is single master.

You can't connect two masters (hosts) directly together.

A-A cables are illegal in sense of the USB specs, they don't work and
can even damage the systems.
Thosese cables are mostly sold because in a early USB specification
there was only A connectors and a early hardware designs used A
connectors instead of B.
I personally would avoid such hardware.

There are other options to connects computers together via USB.
- Use two USB-Ethernet adapters and X-link them together and
  do Ethernet.
- Use two USB-serial adapters and X-link them together and do
  ppp, slip, xmomdem or whatever.
- Use a special host to host adapter - those simulate an serial
  adapter at each host side.
  AFAIK those adapters are all limited to USB-1.1 speed, so the
  Ethernet way can be faster if both sides can do high speed.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de