Cisco Systems OL-11497-03 manual Sram, Total Dram Product Numbers Dram Sockets

Chapter 1 Product Overview

Route Processors

Table 1-2		GRP DRAM Configurations
Total DRAM		Product Numbers	DRAM Sockets		Number of DIMMs
128	MB1	MEM-GRP/LC-64(=)	U39	(bank 1) and	2 64-MB DIMMs
			U42	(bank 2)
128	MB	MEM-GRP/LC-128(=)	U39	(bank 1)	1 128-MB DIMM
256	MB	MEM-GRP/LC-256(=)	U39	(bank 1) and	2 128-MB DIMMs
			U42	(bank 2)

1. 128 MB is the standard (default) DRAM configuration for the GRP.

Caution To prevent memory problems, DRAM DIMMs must be 3.3-volt (V), 60-nanosecond (ns) devices. Do not install other devices in the DIMM sockets. Cisco recommends that you use the Cisco-approved memory options listed in Table 1-2.

SRAM

SRAM provides secondary CPU cache memory. The standard GRP configuration is 512 KB. Its principal function is to act as a staging area for routing table updates and for information sent to and received from line cards. SRAM is not user configurable and cannot be upgraded in the field.

NVRAM

NVRAM provides 512 KB of memory for system configuration files, software register settings, and environmental monitoring logs. This information is backed up with built-in lithium batteries that retain the contents for a minimum of five years. NVRAM is not user configurable and cannot be upgraded in the field.

Flash Memory

Flash memory allows you to remotely load and store multiple Cisco IOS software and microcode images. You can download a new image over the network or from a local server and then add the new image to Flash memory or replace the existing files. You then can boot the routers either manually or automatically from any of the stored images.

	Cisco 12006 and Cisco 12406 Router Installation and Configuration Guide
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