Juniper Networks M160 manual Routing Engine Functions, Routing Engine Architecture

M160 Internet Router Hardware Guide

Figure 24: Routing Engine Architecture

	System		Routing	Control
	management		protocols	functions
JUNOS
	processes
software
			Kernel
		Intel-based PCI platform

Routing Engine Functions

System processes

Operating system

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The Routing Engine handles all routing protocol processes, as well as the software processes that control the router’s interfaces, the chassis components, system management, and user access to the router. These routing and software processes run on top of a kernel that interacts with the Packet Forwarding Engine. For more information about the processes, see Routing Engine Software Components on page 43.

The Routing Engine includes the following functions and features:

Processing of routing protocol packets—The Routing Engine handles all packets that concern routing protocols, freeing the Packet Forwarding Engine to handle only packets that represent Internet traffic.

Software modularity—Because each software process is devoted to a different function and uses a separate process space, the failure of one process has little or no effect on the others.

In-depth Internet functionality—Each routing protocol is implemented with a complete set of Internet features and provides full flexibility for advertising, filtering, and modifying routes. Routing policies are set according to route parameters (for example, prefix, prefix lengths, and Border Gateway Protocol [BGP] attributes).

Scalability—The JUNOS routing tables have been designed to hold all the routes in current networks with ample capacity for expansion. Additionally, the

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