T640 T Series Control Boards (T-Cbs) Description; Figure 21: T-Cb - Juniper T640 Hardware Manual

T640 Core Router Hardware Guide
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T640 T Series Control Boards (T-CBs) Description

38
NOTE: The LEDs on the Routing Engine do not necessarily indicate
routing-related activity.
Replacing a T640 Routing Engine on page 206
T640 Routing Engine Functions on page 8
Maintaining the T640 Routing Engines on page 148
This chassis supports up to two T-CBs. The Routing Engine requires an adjacent T-CB
to provide control and monitoring functions for the router (see Figure 21 on page 38).
These functions include determining Routing Engine mastership, controlling power and
reset for the other router components, monitoring and controlling fan speed, and
monitoring system status.
You can install up to two T-CBs in the router. Control boards install into the upper rear
of the chassis in the slots labeled
bottom). If two T-CBs are installed, one functions as the master and the other as its
backup. If the master fails or is removed, the backup restarts and becomes the master.
Each T-CB requires a Routing Engine to be installed in the adjacent slot.
above , and installs below
RE0 CB1
present in the adjacent slot.
If the host system is redundant, the backup T-CB is hot-removable and hot-insertable,
but the master T-CB is hot-pluggable. A T-CB that is not redundant is hot-pluggable.

Figure 21: T-CB

NOTE: The T-CB requires Junos OS Release 7.0 or later.
and (referred to as
CB0 CB1
. T-CBs cannot function if a Routing Engine is not
RE1
Copyright © 2010, Juniper Networks, Inc.
and , top to
CB-0 CB-1
CB0 installs