Token Ring Interface Processor (TRIP) Installation and Configuration 13
Installation Prerequisites
Online Insertion and Removal—An Overview
Online insertion and removal (OIR) allows you to remove and replace interface processors while the
system is operating; you do not need to notify the software or shut down the system power. This
section describes the mechanical functions of the system components and stresses the importance of
following the correct procedures to avoid unnecessary restarts or card failures. This section is for
background information only. Subsequent sections provide specific procedures for removing and
installing a TRIP. All CxBus and CyBus interface processors support OIR
Each processor module contains a bus connector with which it connects to the system backplane.
The bus connector is a set of tiered pins, in three lengths. The pins send specific signals to the system
as they make contact with the backplane. The system assesses the signals it receives and the order
in which it receives them to determine what event is occurring and what task it needs to perform,
such as reinitializing new interfaces or shutting down removed ones. For example, when you insert
an interface processor, the longest pins make contact with the backplane first, and the shortest pins
make contact last. The system recognizes the signals and the sequence in which it receives them. The
system expects to receive signals from the individual pins in this logical sequence, and the ejector
levers help to ensure that the pins mate in this sequence.
When you remove or insert an interface processor, the backplane pins send signals to notify the
system, which then performs as follows:
1
Rapidly scans the backplane for configuration changes and does not reset any interfaces.
2
Initializes all newly inserted interface processors, noting any removed interfaces and placing
them in the administratively shutdown state.
3
Brings all previously configured interfaces on the interface processor back to the state they were
in when they were removed. Any newly inserted interfaces are put in the administratively shut
down state, as if they were present (but unconfigured) at boot time. If a similar interface processor
type has been reinserted into a slot, then its ports are configured and brought online up to the port
count of the original interface processor.
OIR functionality enables you to add, remove, or replace interface processors with the system
online, which provides a method that is seamless to end users on the network, maintains all routing
information, and ensures session preservation.
When you insert a new interface processor, the system runs a diagnostic test on the new interfaces
and compares them to the existing configuration. If this initial diagnostic test fails, the system
remains off line for another 15 seconds while it performs a second set of diagnostic tests to
determine whether or not the interface processor is faulty and if normal system operation is possible.
If the second diagnostic test passes, which indicates that the system is operating normally and the
new interface processor is faulty, the system resumes normal operation but leaves the new interfaces
disabled. If the second diagnostic test fails, the system crashes, which usually indicates that the new
interface processor has created a problem on the bus and should be removed.
The system brings online only interfaces that match the current configuration and were previously
configured as up; all other interfaces require that you configure them with the configure command.
On interface processors with multiple interfaces, only the interfaces that have already been
configured are brought online. The new interface remains in the administratively shutdown state
until you configure it and bring it online.
Caution
While the TRIP supports OIR, the system may indicate a hardware failure if you fail to
follow proper procedures.
