Bash redirection problem

From: patrick carosso (carossopatrick_at_yahoo.it)
Date: 12/22/04 

Date: Wed, 22 Dec 2004 20:51:04 GMT

Hello,
Is it possible to have process1 output sent to process2 input
and at the same time have process2 output sent do process1 input?

I know, this works for one direction:

process1 | process2

but for the other?

Thanks!