Juniper Networks M5, M10 manual Packets Out

Routing Engine Architecture

•Monitoring efficiency and flexibility—The router supports functions such as alarm handling and packet counting on every port, without degrading packet-forwarding performance.

The Routing Engine constructs and maintains one or more routing tables. From the routing tables, the Routing Engine derives a table of active routes, called the forwarding table, which is then copied into the Packet Forwarding Engine. The design of the ASICs allow the forwarding table in the Packet Forwarding Engine to be updated without interrupting forwarding performance. See Figure 15.

Figure 15: Control Packet Handling for Routing and Forwarding Table Updates

Forwarding table updates

Packets

in

Routing protocol

process

Routing Engine

Forwarding table

Packet Forwarding

Engines

Routing protocol packets from network

Packets

out

1240

System Architecture Overview 33