Juniper JUNOS 10.2, Upgrade Manual

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Chapter 2
Hardware Architecture
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Hardware Architecture Overview on page 13
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M Series, MX Series, T Series, TX Matrix, and TX Matrix Plus Routers on page 14
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J Series Routers on page 19
Hardware Architecture Overview
Juniper Network routing platforms are made up of two basic routing components:
■
Routing Engine—The Routing Engine controls the routing updates and system
management.
■
Packet Forwarding Engine (PFE)—The Packet Forwarding Engine performs
Layer 2 and Layer 3 packet switching, route lookups, and packet forwarding.
From a system administration perspective, you install the software onto the Routing
Engine and during the installation, the appropriate software is forwarded to other
components as necessary. Each Routing Engine includes a CompactFlash card that
stores the JUNOS Software. On the M Series, MX Series, T Series, and TX Matrix
routers, the system also includes a hard drive that acts as a backup boot drive. The
TX Matrix Plus router includes either a hard drive or a solid state drive as a backup
boot drive.
NOTE: The MX80 router is a single-board router with a built-in Routing Engine and
single Packet Forwarding Engine. On an MX80 router, the JUNOS Software is stored
on dual, internal NAND flash devices. These devices provide the same functionality
as a CompactFlash card and hard drive.
On routing platforms with dual Routing Engines, each Routing Engine is independent
with regard to upgrading the software. To install new software on both Routing
Engines, you need to install the new software on each Routing Engine. On platforms
with dual Routing Engines configured for high availability, you can use the unified
in-service software upgrade procedure to upgrade the software. For more information
on this procedure, see the
JUNOS High Availability Configuration Guide .
Hardware Architecture Overview
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