SSH PHP

Does you now evereone about programing ssh for configure ethernet swith
DES-3526 .If you now somewone who can help me give me hi`s malL.
t would be great if
you could help me out
My problem is:
a connected to switch using ssh2_auth_password($connection,
'username', 'secret'))
sucsessfully
but a can`t
open shell ssh2_shell($connection, 'vt100' );
and a cant execute comands using ssh2_exec($connection, 'comand');
What can i do to write data to the switch&

> This is a simple example
> > <?php
> >
> > $connection = ssh2_connect("ethernet switch adress", 22);
> > ssh2_auth_password($connection,"login","pass");
> >
> > $stream = ssh2_shell($connection, 'vt100');
> >
> > ?>
> >
> > this is not work
> > and when i use ssh2_exec($connection, 'comand');
> > a have error message
> > can execute comands
> >
> > What can i do for write commands to ethernet switch?

"I have error message"




Can you help me?