Communication between SAP R/3 and WebAS 6.40

Hi,

I've a system made by an SAP R/3 4.6C on a server and a WebAS 6.40 on another server.

My question is :

Can WebAS 6.40 communicates with R/3 system calling BAPI using Jco Connector? .

Is it mandatory to install a WP-PI on R/3 ?