BIZ files are firmware images--software that runs in the router itself. No special software is required to manage NetVanta or other AOS products, rather, http(s)/SSH/telnet/serial connections allow you to configure and manage via a web GUI or command line. All of the relevant documentation for that hardware and software is available here on the support community. If you need to learn how to do something specific (e.g., DHCP pools), just search that protocol or application by name. AOS devices all handle roles and services in a similar way, so an application brief will apply to your 3200 as well as other units. Of course, you're welcome to ask for help here too!