System Architecture Overview

The router architecture consists of two major components:

• Packet Forwarding Engine—Performs Layer 2 and Layer 3 packet switching, route lookups, and packet forwarding.
• Routing Engine—Provides Layer 3 routing services and network management.

The Packet Forwarding Engine and the Routing Engine perform independently but communicate constantly through a 100-Mbps internal link. This arrangement provides streamlined forwarding and routing control and the ability to run Internet-scale networks at high speeds. Figure 11 illustrates the relationship between the Packet Forwarding Engine and the Routing Engine.

Figure 11: System Architecture

For a discussion of the architectural components, see the following sections:

• Packet Forwarding Engine Architecture
• Routing Engine Architecture