Interfaces Overview
For the interfaces on a router to function, you must configure them, specifying properties such as the interface location (that is, which slot the Flexible PIC Concentrator (FPC) is installed in and which location on the FPC the Physical Interface Card (PIC) is installed in), the interface type (such as SONET or ATM), encapsulation, and interface-specific properties. You can configure the interfaces that are currently present in the router, and you can also configure interfaces that are not currently present but that you might add in the future. When a configured interface appears, the JUNOS software detects its presence and applies the appropriate configuration to it.
For information about which PICs are supported on your platform, see your platform's PIC guide.