[Contents] [Prev] [Next] [Index] [Report an Error]

ATM NBMA

The software supports nonbroadcast multiaccess (NBMA) networks, which interconnect more than two routers and have no broadcast capabilities.

Note: The E120 router and the E320 router do not support ATM NBMA in the current release.

An ATM NBMA network can be thought of as an interface stack with a single IP interface at the top, eventually fanning out to multiple independent PVCs. See Figure 2.

Figure 2: NBMA Interface Stack

Image g013697.gif

Unlike standard point-to-point ATM interfaces and broadcast-oriented Ethernet interfaces, NBMA interfaces form a point-to-multipoint connection. For example, you can use NBMA to connect a router to multiple stations.

An NBMA interface consists of a single ATM 1483 subinterface that has two or more VCs. You can add circuits to an existing ATM 1483 subinterface at any time. New circuits become usable after they have valid ARP table entries. NBMA circuits support only IP directly over ATM 1483.

The software restricts NBMA interfaces so that all circuits reside on the same physical interface. An NBMA interface can use as many PVCs as are available on a physical port.

[Contents] [Prev] [Next] [Index] [Report an Error]