Cisco XR 12404 - Manual (Page 31)

1-17
Cisco XR 12404 Router Installation Guide
OL-13830-02
Chapter 1 Cisco XR 12404 Router Overview
Route Processor
Table 1-6 PRP3 DDR2 DRAM Configuration
PRP SRAM
Static Random Access Memory (SRAM) provides 2 MB of secondary CPU cache
memory. Its principal function is to act as a staging area for routing table updates,
and for information sent to and received from the line cards. SRAM is not
user-configurable and cannot be upgraded in the field.
PRP NVRAM
Non-volatile Random Access Memory (NVRAM) provides 2 MB of memory for
system configuration files, software register settings, and environmental
monitoring logs. Built-in lithium batteries retain the contents of NVRAM for a
minimum of 5 years. NVRAM is not user configurable and cannot be upgraded in
the field.
PRP Flash Memory
Use flash memory to store multiple Cisco IOS XR software and microcode
images that you can use to operate the router. You can download new images to
flash memory over the network (or from a local server) to replace an existing
image, or to add it as an additional image. The router can be booted (manually or
automatically) from any of the stored images in flash memory.
Flash memory also functions as a Trivial File Transfer Protocol (TFTP) server to
allow other servers to boot remotely from the stored images, or to copy them into
their own flash memory.
The system uses two types of flash memory on PRP-2:
• Onboard flash memory (called bootflash)—Contains the Cisco IOS boot
image
• Flash memory disks (or cards)—Contain the Cisco IOS software image
Total SDRAM SDRAM Sockets Number of DIMMs
4 GB U8 (bank 1)
U10 (bank 2)
Two 2 GB DIMMs
8 GB U8 (bank 1)
U10 (bank 2)
Two 4 GB DIMMs
todd.book Page 17 Monday, March 16, 2009 2:47 PM