# Before You Configure ATM

Before you configure an ATM interface, verify that you have installed the physical module (such as an OC3 module) correctly. For more information about preconfiguration procedures, see the ERX Hardware Guide or the E120 and E320 Hardware Guide.

Also have the following information available:

- Interface specifiers for the ATM interfaces that you want to create

  For more information about specifying ATM interfaces and subinterfaces on E Series routers, see Interface Types and Specifiers in JunosE Command Reference Guide.

- Virtual path and channel numbers for each virtual circuit you want to create
- IP addresses and subnet mask assignments for IP interfaces

You can configure the following types of dynamic interfaces over ATM:

- IP over static ATM 1483 (IPoA)
- IP over PPP over static ATM 1483
- IP over PPPoE over static ATM 1483
- IP over bridged Ethernet over static ATM 1483
- IP over MLPPP over static ATM 1483
- ATM 1483 over static ATM AAL5 over ATM

For information about creating these dynamic configurations, see Configuring Dynamic Interfaces.