Related
Documentation
T4000 Router Description on page 3
•
•
T4000 Component Redundancy on page 15
T4000 Component Redundancy
The T4000 Core Router is designed so that no single point of failure can cause the entire
system to fail. The following major hardware components are redundant:
•
Switch Interface Boards (SIBs)—The router has five SIBs. For more information, see
“T4000 Switch Interface Board (SIB) Description” on page 46
.
•
Host subsystem—The host subsystem consists of a Routing Engine functioning together
with a control board. The router can have one or two host subsystems. If two host
subsystems are installed, one functions as the master and the other functions as the
backup. If the master host subsystem (or either of its components) fails, the backup
can take over as the master. To operate, each host subsystem requires a Routing Engine
installed in an adjacent slot to a control board. For more information, see
“T4000
RE-C1800 Routing Engine Description” on page 40
,
“T4000 LCC-CB” on page 37
, and
“T4000 Host Subsystem Description” on page 35
.
If the Routing Engines are configured for nonstop active routing, the backup Routing
Engine automatically synchronizes its configuration and state with the master Routing
Engine. Any update to the master Routing Engine state is replicated on the backup
Routing Engine. If the backup Routing Engine assumes mastership, packet forwarding
continues through the router without interruption. For more information about nonstop
active routing, see the
Junos OS High Availability Library for Routing Devices
.
•
SONET Clock Generators (SCGs)—The router has a standard configuration of one
SCG. A second can be purchased to function as backup. If one SCG fails, the other
becomes the master SCG. Mastership of the SCGs is independent of the host subsystem,
so routing functions are not affected. For more information, see
“T4000 SONET Clock
Generators (SCGs) Description” on page 49
.
•
Power supplies—The router has two power supplies, which share the load evenly. If
one power supply fails, the other power supply can provide full power to the router
indefinitely. For more information, see
“T4000 Power System Description” on page 43
.
•
Cooling system—The cooling system has redundant components, which are controlled
by the host subsystem. If one of the fans fails, the host subsystem increases the speed
of the remaining fans to provide sufficient cooling for the router indefinitely. For more
information, see
“T4000 Cooling System Description” on page 21
.
Related
Documentation
T4000 Router Description on page 3
•
T4000 Chassis Description
The T4000 Core Router chassis is a rigid sheet metal structure that houses all the other
router components (see
Figure 6 on page 17
and
Figure 7 on page 18
). The chassis
15
Copyright © 2013, Juniper Networks, Inc.
Chapter 3: T4000 Hardware Components Overview
Summary of Contents for T4000 -
Page 1: ...T4000 Core Router Hardware Guide Published 2013 08 28 Copyright 2013 Juniper Networks Inc ...
Page 18: ...Copyright 2013 Juniper Networks Inc xviii T4000 Router Hardware Guide ...
Page 26: ...Copyright 2013 Juniper Networks Inc 2 T4000 Router Hardware Guide ...
Page 30: ...Copyright 2013 Juniper Networks Inc 6 T4000 Router Hardware Guide ...
Page 36: ...Copyright 2013 Juniper Networks Inc 12 T4000 Router Hardware Guide ...
Page 78: ...Copyright 2013 Juniper Networks Inc 54 T4000 Router Hardware Guide ...
Page 90: ...Copyright 2013 Juniper Networks Inc 66 T4000 Router Hardware Guide ...
Page 98: ...Copyright 2013 Juniper Networks Inc 74 T4000 Router Hardware Guide ...
Page 100: ...Copyright 2013 Juniper Networks Inc 76 T4000 Router Hardware Guide ...
Page 108: ...Copyright 2013 Juniper Networks Inc 84 T4000 Router Hardware Guide ...
Page 144: ...Copyright 2013 Juniper Networks Inc 120 T4000 Router Hardware Guide ...
Page 168: ...Copyright 2013 Juniper Networks Inc 144 T4000 Router Hardware Guide ...
Page 176: ...Copyright 2013 Juniper Networks Inc 152 T4000 Router Hardware Guide ...
Page 178: ...Copyright 2013 Juniper Networks Inc 154 T4000 Router Hardware Guide ...
Page 190: ...Copyright 2013 Juniper Networks Inc 166 T4000 Router Hardware Guide ...
Page 200: ...Copyright 2013 Juniper Networks Inc 176 T4000 Router Hardware Guide ...
Page 202: ...Copyright 2013 Juniper Networks Inc 178 T4000 Router Hardware Guide ...
Page 212: ...Copyright 2013 Juniper Networks Inc 188 T4000 Router Hardware Guide ...
Page 314: ...Copyright 2013 Juniper Networks Inc 290 T4000 Router Hardware Guide ...
Page 354: ...Copyright 2013 Juniper Networks Inc 330 T4000 Router Hardware Guide ...
Page 358: ...Copyright 2013 Juniper Networks Inc 334 T4000 Router Hardware Guide ...
Page 389: ...PART 6 Index Index on page 367 365 Copyright 2013 Juniper Networks Inc ...
Page 390: ...Copyright 2013 Juniper Networks Inc 366 T4000 Router Hardware Guide ...