Juniper Networks J-series Services Router J2320 - Manual (Page 53)

J4350 and J6350 Midplane
The midplane is located in the center of the chassis and forms the rear of the PIM
card cage (see Figure 18 on page 30). You install the PIMs into the midplane from
the front of the chassis. Data packets are transferred across the midplane from the
PIM to the Routing Engine, and from the Routing Engine across the midplane to the
destination PIM.
J4350 and J6350 Routing Engine Hardware
The Routing Engine consists of the following components. For more information,
see “Software Overview” on page 39.
■ Processor—Creates the packet forwarding switch fabric for the router and runs
JUNOS software to maintain the router's routing tables and routing protocols.
■ DRAM—Buffers incoming packets and provides storage for the routing and
forwarding tables and for other Routing Engine processes.
To view the amount of DRAM installed on your router, issue the show chassis
routing-engine command.
■ EPROM—Stores the serial number of the Routing Engine.
To view the serial number of the Routing Engine, issue either the show chassis
routing-engine command or the show chassis hardware command.
■ Crypto Accelerator Module—Processor card that enhances performance of
cryptographic algorithms used in IP security (IPSec) services. The cryptographic
algorithms supported include Advanced Encryption Standard (AES), Data
Encryption Standard (DES), triple DES (3DES), Hashed Message Authentication
Code-Message Digest 5 (HMAC-MD5), and HMAC-Secure Hash Algorithm 1
(SHA-1).
To determine whether there is a Crypto Accelerator Module installed on your
router, issue the
show chassis hardware command.
■ Compact flash—Provides primary storage for software images, configuration
files, and microcode. J4350 and J6350 routers have a slot on the motherboard
for an internal compact flash. For information about replacing the compact flash,
see “Replacing Internal Compact Flashes on J4350 and J6350
Routers” on page 181.
J4350 and J6350 Boot Devices
The J4350 and J6350 Services Routers can boot from two devices:
■ Internal compact flash
■ USB storage device
Normally, the J4350 or J6350 Services Router boots from the internal compact flash.
If the compact flash fails, the router attempts to boot from the USB storage device.
J4350 and J6350 Services Router Hardware Features ■ 31
Chapter 2: System Overview