Juniper Networks M10i manual System Architecture Overview, Packet Forwarding Engine Architecture

Chapter 4

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 on page 33

■Routing Engine Architecture on page 35

Packet Forwarding Engine Architecture

The Packet Forwarding Engine performs Layer 2 and Layer 3 packet switching. It can forward up to 16 million packets per second (Mpps) for all packet sizes. The aggregate throughput is 3.2 gigabits per second (Gbps) full duplex per FPC (6.4 Gbps full-duplex total throughput rate). The Packet Forwarding Engine is implemented in application-specific integrated circuits (ASICs). It uses a centralized route lookup engine and shared memory.

The Packet Forwarding Engine architecture includes the following components:

Packet Forwarding Engine Architecture ■ 33