Apple AirPort Time Capsule 802.11n (3rd Generation) - Manual (Page 18)

18 Chapter 2 Setting Up Your Time Capsule
3 Follow the onscreen instructions to set up your Time Capsule and your wireless
network.
The AirPort Utility setup assistant asks you questions about the type of network you
want to use and the services you want to set up, and helps you enter the appropriate
settings.
If you’re using your Time Capsule to connect to the Internet, you need a broadband
(DSL or cable modem) account with an Internet service provider (ISP), or a connection
to the Internet using an existing Ethernet network. If you received specific information
from your ISP (such as a static IP address or a DHCP client ID), you may need to enter it
in AirPort Utility. Have this information available when you set up your Time Capsule.