Chapter 3 NPE-300 and NPE-400 Overview
NPE-300 and NPE-400 Description and Overview
•Upgradable memory modules
The NPE-300 and NPE-400 use SDRAM for storing all packets received or sent from network interfaces. The SDRAM also stores routing tables and network accounting applications.
–On the NPE-300, two independent SDRAM memory arrays in the system allow concurrent access by port adapters and the processor; however, only one is upgradable.
–On the NPE-400, one memory array is shared by port adapters and the processor.
•Cache memory
The NPE-300 and NPE-400 have cache SRAM that functions as the tertiary cache for the microprocessor.
•Two environmental sensors for monitoring the cooling air as it leaves the chassis for both the NPE-300 and NPE-400
•Boot ROM for storing sufficient code for booting the Cisco IOS software
Note The NPE-300 and the NPE-400 do not have packet SRAM.
System Management Functions
The network processing engines perform the following system management functions:
•Sending and receiving routing protocol updates
•Managing tables, caches, and buffers
•Monitoring interface and environmental status
•Providing Simple Network Management Protocol (SNMP) management through the console and Telnet interface
•Accounting for and switching of data traffic
•Booting and reloading images
•Managing port adapters (including recognition and initialization during online insertion and removal)
Terms and Acronyms
•Cache—Memory with fast access and small capacity used to temporarily store recently accessed data; found either incorporated into the processor or near it.
•DIMM—dual in-line memory module
•DRAM—dynamic random-access memory
•Instruction and data cache—Instructions to the processor, and data on which the instructions work.
•Integrated cache—Cache that is built into the processor; sometimes referred to as internal cache. Cache memory physically located outside the processor is not integrated, and is sometimes referred to as external cache.
•OTP—one time programmable
Network Processing Engine and Network Services Engine Installation and Configuration
