Juniper Networks M5 - Manual (Page 53)

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
Packets
in
Packets
out
Packet Forwarding
Engines
Forwarding table
Forwarding table
updates
Routing protocol
packets from network
Routing Engine
Routing protocol
process
1240
System Architecture Overview 33