Product Overview
•Providing an auxiliary port for other external equipment (such as modems)
•Providing an IEEE 802.3, 10/100-megabits-per-second (Mbps) Ethernet port for Telnet functionality
•Running routing protocols
•Building and distributing routing tables to the line cards
•Providing general system maintenance functions
•Communicating with the line cards either through the switch fabric or through the maintenance bus (MBus)
The MBus connection allows the GRP to download a system bootstrap image, collect or load diagnostic information, and perform general, internal system maintenance operations. The switch fabric connection is the main data path for routing table distribution as well as for packets that are sent between line cards and the GRP.
GRP Components
The GRP contains the following components:
•RISC processor—IDT R5000 Reduced Instruction Set Computing (RISC) processor used for the CPU. The CPU runs at an external bus clock speed of 100 MHz and an internal clock speed of 200 MHz.
•DRAM—Up to 512 megabytes (MB) of parity-protected, extended data output (EDO) dynamic random-access memory (DRAM) on two 60-nanosecond (ns), dual in-line memory modules (DIMMs). 128 MB of DRAM is the minimum shipping configuration for the GRP.
Note GRP route memory configurations of 512 MB are only compatible with Product Number GRP-B=. In addition, Cisco IOS Release 12.0(19)S or 12.0(19)ST or later and ROMMON Release 11.2 (181) or later are also required.
•SRAM—512 kilobytes (KB) of static random-access memory (SRAM) for secondary CPU cache memory functions. (SRAM is not user configurable or field upgradeable.)
•NVRAM—512 KB of nonvolatile RAM (NVRAM). (NVRAM is not user configurable or field upgradeable.)
•Memory—Most of the additional memory components used by the system, including onboard Flash memory and up to two Personal Computer Memory Card International Association (PCMCIA)-based Flash memory cards and advanced technology attachment (ATA) Flash disks.
•Sensors—Air-temperature sensors for environmental monitoring.
Cisco IOS Software
The Cisco IOS software images that run the Cisco 12000 Series Router system reside in Flash memory, which is located on the GRP in the form of a single in-line memory module (SIMM), and on up to two Flash cards (called Flash memory cards or Flash disks), which insert into the two slots (slot 0 and slot 1) on the front of the GRP. (See Figure 2.)
Note
GRP Components
