Users in the Work perimeter also have access inside the company firewall, so IT can also grant access to network file shares. Pictured is a file share maintained by BlackBerry on one of its servers. The files can be access by apps in the Work perimeter, including the Connect to Dropbox and Box apps BlackBerry included with the Work perimeter setup. Your IT staff can, of course, pick which apps are and are not included in the Work perimeter.
By the same token, users may access Web sites inside the firewall when in the Work perimeter.