Cisco 7200 VXR - Manual (Page 58)

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Cisco 7200 VXR Installation and Configuration Guide
OL-5013-09
Chapter 1 Cisco 7200 VXR Product Overview
Functional Overview
Note The Port Adapter Jacket Card does not support OIR. However, the port adapter installed in the Port
Adapter Jacket Card does support OIR.
Note As you disengage the port adapter from the router or switch, online insertion and removal (OIR)
administratively shuts down all active interfaces in the port adapter.
OIR allows you to install and replace port adapters and service adapters while the router is operating;
you do not need to notify the software or shut down the system power, although you should not run traffic
through the port adapter you are removing while it is being removed. OIR is 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 adapter or service adapter in a Cisco 7200 VXR router,
refer to the online configuration note for each port adapter 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 network services 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 adapter 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 adapter or service adapter. The system assesses the signals it receives
and the order in which it receives them to determine if a port adapter 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 adapter or service
adapter, the longest pins make contact with the port adapter 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 adapter or service adapter in a Cisco 7200 VXR router, the midplane
pins send signals to notify the system, which then performs as follows:
1. Rapidly scans the midplane for configuration changes.
2. Initializes all newly inserted port adapters or service adapters, noting any removed interfaces and
placing them in the administratively shutdown state.
3. Brings all previously configured interfaces on the port adapter back to the state they were in when
they were removed. Any newly inserted interfaces are put in the administratively shutdown state, as
if they were present (but not configured) at boot time. If a similar port adapter type is reinserted into
a slot, its ports are configured and brought online up to the port count of the original port adapter.
(A service adapter has no configurable ports.)