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Network Processing Engine and Network Services Engine Installation and Configuration
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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