Chapter 1
Cisco 7200 VXR Product Overview
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Packet SRAM for storing packets of information in preparation for fast switching
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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
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Two environmental sensors for monitoring the cooling air as it leaves the chassis
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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
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Managing tables, caches, and buffers
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Monitoring interface and environmental status
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Providing Simple Network Management Protocol (SNMP) management through the console and
Telnet interface
Accounting for and switching of data traffic
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OL-5013-08
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.
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.)
Cisco 7200 VXR Installation and Configuration Guide
Field-Replaceable Units
1-13