The 320B is just that, A MODEM only. It does not have any DCHP services that hand out IP addresses to devices that connect to the back. If this is the only device being connected to the modem, the modem should pass along the static ISP IP address it's getting from the ISP. You may need to input the DSL account information into Windows networking or connection settings to tell Windows that this pc is directly connected to a modem that is handing off DSL account information and Windows has to authenticate thru the Modem to gain access to the Internet.
Or, you might get a dedicated external router, which is preferred, then this will handle the DSL account connection to the modem and the router will then give you DHCP IP addressing services. Then all you need to do is set up Windows networking to Auto Obtain IP addresses from the host router.
So if you choose in connecting a router, it would look like this:
DSL-320B>DIR Series Router<>Wired PCs and or wireless devices can connect to the router.
Depending on what your wireless needs are, if any, I recommend checking out one of the following DIR series routers to use in conjunction with the dsl modem:
2.4Ghz only wireless
DIR-645, DIR-655.
If you need or want any both 2.4Ghz and 5Ghz wireless:
DIR-857, DIR-827, DIR-835 or DIR-825
Not sure what models would be available in your region. You should call D-Link and talk to a sale rep.
Let us know how it goes.