Chapter 1 Cisco 7200 VXR Product Overview
Field-Replaceable Units
–The NPE-100, NPE-150, and NPE-200 use DRAM for storing routing tables, network accounting applications, packets of information in preparation for process switching, and packet buffering for SRAM overflow (except in the NPE-100, which contains no packet SRAM). The standard configuration is 32 MB, with up to 128 MB available through single in-line memory module (SIMM) upgrades.
•Packet SRAM for storing packets of information in preparation for fast switching
The NPE-150 has 1 MB of SRAM and the NPE-200 has 4 MB of SRAM. No other network processing engine or network services engine has SRAM.
•Cache memory
–The NPE-G2 has two levels of cache: a primary and a secondary cache that are internal to the microprocessor, with the secondary unified cache for data and instruction.
–The NPE-G1 has two levels of cache: a primary and a secondary cache that are internal to the microprocessor, with the secondary unified cache for data and instruction.
–The NSE-1 has three levels of cache: a primary and a secondary unified cache that are internal to the microprocessor, and a tertiary 2-MB external cache.
–The NPE-400 has three levels of cache: a primary and a secondary cache that are internal to the microprocessor, and a tertiary 4-MB external cache that provides additional high-speed storage for data and instructions.
–The NPE-300 has three levels of cache: a primary and a secondary cache that are internal to the microprocessor, and a tertiary 2-MB external cache that provides additional high-speed storage for data and instructions.
–The NPE-225 has two levels of cache: a primary cache that is internal to the processor and a secondary 2-MB external cache that provides additional high-speed storage for data and instructions.
–The NPE-200 has unified cache SRAM that functions as the secondary cache for the microprocessor. (The primary cache is within the microprocessor.)
–The NPE-175 has two levels of cache: a primary cache that is internal to the processor and a secondary 2-MB external cache that provides additional high-speed storage for data and instructions.
–The NPE-150 has unified cache SRAM that functions as the secondary cache for the microprocessor. (The primary cache is within the microprocessor.)
–The NPE-100 has unified cache SRAM that functions as the secondary cache for the microprocessor. (The primary cache is within the microprocessor.)
•Two environmental sensors for monitoring the cooling air as it leaves the chassis
•Boot ROM for storing sufficient code for booting the Cisco IOS software; the NPE-G2, NPE-G1, NSE-1, NPE-400, NPE-300, NPE-225, NPE-200, and NPE-175 have boot ROM.
The network processing engines and network services engine 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
Cisco 7200 VXR Installation and Configuration Guide
