Sounds like a WordPress question?
bbPress and WordPress both use cookies not sessions for storing the state. Not sure how you would go about this.
for example, for phpbb2: http://www.phpbb.com/kb/article/phpbb2-sessions-integration/
i would like to display the login form and menu in others page.
Sounds more like a PHP question than either a bbPress or WordPress question. Sessions are outside the scope of what’s built in to bbPress and WordPress (unless I am completely off.)
but how to display the admin menu (admin link) in the header of my wordpress, when i’m connected to bbpress?
thanks 
To have access to bbPress functions from WordPress, you need to include bbPress inside WordPress. Then you can put that link wherever you want using bbPress functions. Read here:
http://www.adityanaik.com/integratepress-part-i/
Find bb-load.php in that page.
re,
i have modified wp-config.php and bb-config.php, but in the forum, all name have been erased and all people are “anonymous”… why?
Bye
“UPDATE: These steps are valid for previous version of BBPress. May not work with WP 2.6.X and BBpress Alpha”
how to make sessions outside bbpress with wp 2.7 and bbpress 1.0 alpha6 ?
bye
