Cisco Systems OL-1911-05 manual Overview of the ATM Router Module, 24-2

Chapter 24 Configuring ATM Router Module Interfaces

Overview of the ATM Router Module

Overview of the ATM Router Module

The ATM router module allows you to integrate Layer 3 routing and ATM switching within a single chassis. When you install the ATM router module, you no longer need to choose either Layer 3 or ATM technology, as is frequently the case with enterprise, campus, and MAN applications.

The ATM router module can perform one or more of the functions described in Figure 24-1.

Figure 24-1 ATM Router Module Routing and Bridging Functions

ATM to ATM bridging

ATM

Subnet A

ATM

Subnet A

ATM switch

IP routing of ATM to or from ATM and Ethernet

ATM

Subnet B

ATM switch

ATM to ATM routing

ATM

Subnet B

ATM switch

ATM

Subnet A

ATM

Subnet A

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The ATM router module receives Address Resolution Protocol (ARP) messages and route broadcasts from connected ATM peers and sends the appropriate control information to the route processor. On the ATM side, the ATM router module connects to the switching fabric as would any other interface module.

On the Catalyst 8540 MSR, the ATM router module supports LANE clients (LECs), but not LANE servers (LES, LECS, and BUS). It separates the control and data path so that all LANE control messages are handled by the route processor, and data messages are switched on the ATM router module port, as shown in Figure 24-2. The LEC is configured on the ATM router module interface, but control message traffic is sent to the route processor by the ATM router module. The ATM router module sends all ATM data traffic to the appropriate VCs.

ATM and Layer 3 Switch Router Software Configuration Guide

24-2 OL-1911-05