Atm Interfaces; Atm Physical Connections; Figure 1: Atm Interface Column - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - LINK LAYER CONFIGURATION GUIDE 2010-10-13 Configuration Manual

JunosE 11.3.x Link Layer Configuration Guide

ATM Interfaces

ATM Physical Connections

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An ATM port can have a major interface and one or more subinterfaces. An ATM
subinterface is a mechanism that enables a single physical ATM interface to support
multiple logical interfaces. Several logical interfaces can be associated with a single
physical interface.
ATM subinterfaces meet the specifications in RFC 2684—Multiprotocol Encapsulation
over ATM Adaptation Layer 5 (September 1999), which replaces RFC 1483. All references
to ATM subinterfaces in this chapter are still to ATM 1483 subinterfaces.
ATM 1483 subinterfaces are identified by user-defined numbers. To select a subinterface,
you append a subinterface number to the port-level interface atm command.
When you create an ATM 1483 subinterface, you must configure a permanent virtual
circuit (PVC). Protocols such as ATM require one or more virtual circuits over which data
traffic is transmitted to higher layers in the protocol stack.
Figure 1 on page 4 shows a typical point-to-point ATM interface column.

Figure 1: ATM Interface Column

ATM interfaces and subinterfaces support two types of connections—point-to-point and
multipoint. The router defaults to point-to-point.
Point-to-point—Indicates a standard connection; for example, connecting two ATM
end stations
Multipoint—Indicates a single-source end system connected to multiple destination
end systems. Multipoint indicates a nonbroadcast multiaccess (NBMA) interface. See
"ATM NBMA" on page 13.
Depending on the type of connection you choose, you can specify one or more PVCs on
each interface. For a standard point-to-point ATM interface, you configure only one PVC.
For NBMA ATM connections, you configure multiple circuits.
Copyright © 2010, Juniper Networks, Inc.