Cisco 1700 - Manual (Page 28)

Chapter 1 Cisco 1700 Router Overview
1-8
Cisco 1700 Router Hardware Installation Guide
78-5405-03
Router Memory
This section describes the types of memory stored in the router and how to find
out how much of each type of memory is stored in the router.
For instruction on how to upgrade memory in the router, refer to the “Installing
and Upgrading Router Memory” appendix later in this guide.
Types of Memory
The Cisco 1700 router has the following types of memory:
• Dynamic random-access memory (DRAM)—This is the main storage
memory for the router. DRAM is also called working storage and contains the
dynamic configuration information. The Cisco 1700 router stores a working
copy of Cisco IOS software, dynamic configuration information, and routing
table information in DRAM.
• Nonvolatile random-access memory (NVRAM)—This type of memory
contains a backup copy of your configuration. If the power is lost or the router
is turned off, this backup copy enables the router to return to operation
without reconfiguration.
• Flash memory—This special kind of erasable, programmable memory
contains a copy of the Cisco IOS software. The Flash memory structure can
store multiple copies of the Cisco IOS software. You can load a new level of
the operating system in every router in your network and then, when
convenient, upgrade the whole network to the new level. The Flash memory
on the Cisco 1700 router is stored on mini-Flash modules.