Online Insertion And Removal - Cisco 7200 VXR User Manual

Chapter 1 Cisco 7200 VXR Product Overview

Online Insertion and Removal

All port and service adapters in the Cisco 7200 VXR routers support online
insertion and removal (OIR). This function allows you to install and replace port
and service adapters while the router is operating; you do not need to notify the
software or shut down the system power. This provides a method that is seamless
to end users on the network, maintains all routing information, and preserves
sessions.
The following is a functional description of OIR for background information
only; for specific procedures for installing and replacing a port or service adapter
in a Cisco 7200 VXR router, refer to the configuration note that ships with each
port or service adapter.
Caution The network processing engine or network services engine and the
I/O controller are required system components that cannot be
removed if the router is operating. Removing the network processing
engine or the I/O controller while the router is operating causes the
router to shut down or crash and might damage or destroy memory
files.
Each port or service adapter has a bus connector that connects it to the router
midplane. Each midplane connector has a set of tiered pins in three lengths that
send specific signals to the system as they make contact with the port or service
adapter. The system assesses the signals it receives and the order in which it
receives them to determine if a port or service adapter is being removed or
inserted into the midplane. From these signals, the system determines whether to
reinitialize a new interface or shut down a removed interface.
For example, when you insert a port or service adapter, the longest pins make
contact with the port or service adapter first, and the shortest pins make contact
last. The system recognizes the signals and the sequence in which it receives
them.
When you remove or insert a port or service adapter in a Cisco 7200 VXR router,
the midplane pins send signals to notify the system, which then performs as
follows:
1.
2.
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Rapidly scans the midplane for configuration changes.
Initializes all newly inserted port or service adapters, noting any removed
interfaces and placing them in the administratively shutdown state.
Cisco 7200 VXR Installation and Configuration Guide
Functional Overview
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