Switch Availability; Node Redundancy; Node Alarms - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 1 The BPX Switch: Functional Overview

Switch Availability

Cisco WAN hardware and software components are designed to provide a switch availability in excess
of 99.99%. Network availability will be impacted by link failure, which has a higher probability of
occurrence than equipment failure.
Because of this, Cisco WAN network switches are designed so that connections are automatically
rerouted around network trunk failures, often before users detect a problem. System faults are detected
and corrective action taken often before they become service affecting. This section describes some of
the features that contribute to network availability.

Node Redundancy

System availability is a primary requirement with the BPX switch. The designed availability factor of
a BPX switch is (99.99%) based on a node equipped with optional redundancy and a network designed
with alternate routing available. The system software, as well as firmware for each individual system
module, incorporates various diagnostic and self-test routines to monitor the node for proper operation
and availability of backup hardware.
For protection against hardware failure, a BPX switch shelf can be equipped with the following
redundancy options:
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If redundancy is provided for a BPX switch, when a hardware failure occurs, a hot-standby module is
automatically switched into service, replacing the failed module. All cards are hot-pluggable, so
replacing a failed card in a redundant system can be performed without disrupting service.
Since the power supplies share the power load, redundant supplies are not idle. All power supplies are
active; if one fails, then the others pick up its load. The power supply subsystem is sized so that if any
one supply fails, the node will continue to be supplied with adequate power to maintain normal
operation of the node. The node monitors each power supply voltage output and measures cabinet
temperature to be displayed on the NMS terminal or other system terminal.

Node Alarms

Each BPX switch shelf within the network runs continuous background diagnostics to verify the proper
operation of all active and standby cards, backplane control, data, and clock lines, cabinet temperature,
and power supplies. These background tests are transparent to normal network operation.
Each card in the node has front-panel LEDs to indicate active, failed, or standby status.
Each power supply has green LEDs to indicate proper voltage input and output.
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
Redundant common control modules
Redundant crosspoint switch matrixes
Redundant high-speed data and control lines
Redundant power supplies
Redundant high-speed network interface cards
Redundant service interface cards
Cisco BPX 8600 Series Installation and Configuration
Switch Availability
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