split Rx Tx with 2 interfaces??

Jim Thompson jim at netgate.com
Thu Sep 22 12:33:56 PDT 2005

Daniel O'Connor wrote:

> Marcos Biscaysaqu - ThePacific.net wrote:
>> Glenn Dawson wrote:
>>> At 10:42 AM 9/22/2005, Marcos Biscaysaqu - ThePacific.net wrote:
>>>> Hi there.
>>>>    Somebody knows if is possible split the rx and tx traffic in 2 
>>>> differents interfaces, I want to do it with 2 wireless cards (one 
>>>> rx, one tx) , I cant make or I dont know how make it work yet.....
>>>> any ideas?.
>>> What do you hope to gain by doing that?
> You could buy a T/R switch :)
> Not sure if anyone sells off the shelf 2.4Ghz low power TR switches 
> though (wouldn't suprise me if they did, but I suspect they're expensive)

1) yes, its possible.  
2) the real problem is you have to keep the TX side from transmitting 
while the RX side is receiving, or you blow the received packet.  This 
is bad.

This has been done (check my recent resume for 'where', and 'hint' its 
in the current product), but it requires a small amount of external 
logic, and a *very* fast non-maskable interrupt.    (And thats all the 
hint I can give without my ex-employer getting pissed.  Perhaps if they 
go out of business...)

3) you could drive the switch outputs on the tx side to ground except 
when you actually want to transmit, but you still have
the problem in #2 to solve.

More information about the freebsd-current mailing list