Juniper Networks M10i manual High-Availability Chassis Manager HCM, HCM Components

Chapter 2: Hardware Component Overview

For information about the pinouts for the connectors, see “Cable Connector

Pinouts” on page 199.

High-Availability Chassis Manager (HCM)

The High-Availability Chassis Manager (HCM) works with its companion Routing Engine to provide control and monitoring functions for router components. The HCM also displays alarm status and takes PICs online and offline.

Two HCMs are installed into the midplane from the front of the chassis, as shown in Figure 1. The master HCM performs all functions and provides PIC removal buttons for the first FPC. The standby HCM provides PIC removal buttons for the second FPC. The HCM in the slot labeled HCM0 is paired with the Routing Engine in the slot labeled RE0. Likewise, the HCM in the slot labeled HCM1 is paired with the Routing Engine in the slot labeled RE1. By default, the HCM in the slot labeled HCM0 is the master.

NOTE: When HCM mastership changes because of failure, Routing Engine mastership will change as well. For a description of Routing Engine mastership, see “Routing Engine” on page 14.

The HCM performs the following functions:

■Monitoring and control of router components—The HCM collects statistics from all sensors in the system. When it detects a failure or alarm condition, it sends a signal to the Routing Engine, which generates control messages or sets an alarm. The HCM also relays control messages from the Routing Engine to the router components.

■Controlling component power-up and power-down—The HCM controls the power-up sequence of router components as they start and powers down components when their offline buttons are pressed.

■Signaling of mastership—In a router with more than one Routing Engine, the HCM signals to all router components which Routing Engine is the master and which is the standby.

■Alarm display—If an alarm exists, the HCM displays the alarm condition. For more information, see “Alarm LEDs” on page 18.

■PIC removal—If a PIC offline button is pressed, the HCM relays the request to the CFEB, which takes the PIC offline and informs the Routing Engine. Other PICs are unaffected, and system operation continues. For more information, see “PIC Offline Buttons” on page 19.

HCM Components

Each HCM (shown in Figure 6) has the following components:

High-Availability Chassis Manager (HCM) ■ 17