Juniper MX480, Hardware Manual

Page: 135 / 420

MX-Series Switch Control Board (SCB) Overview
At the heart of the MX Series Universal Routers is the Switch and Control Board (SCB).
The SCB has three primary functions: switch data between the line cards, control the
chassis, and house the Routing Engine. The SCB is a single-slot card and has a carrier for
the Routing Engine on the front.
Switch Control Boards control power to MPCs, monitor and control system functions
such as fan speed and the system front panel, and manage clocking, resets, and boots.
Depending on the MX chassis and the level of redundancy, the number of SCBs can vary.
The MX240 and MX480 require two SCBs for 1+1 redundancy, whereas the MX960
requires three SCBs for 2+1 redundancy.
There are four generations of SCBs for MX Series Universal Routers: SCB-MX, SCBE-MX,
SCBE2-MX, and SCBE3-MX.
• SCB-MX is the first-generation switch control board. The SCB-MX is designed to work
with first-generation DPC line cards.
•
The SCBE-MX is the second generation switch control board and is designed specifically
for use with MPC3E line cards to provide full line-rate performance and redundancy
without a loss of bandwidth.
•
The SCBE2-MX provides improved fabric performance for high-capacity line cards
using the third generation fabric XF2 chip (MPC4E, MPC5E, MPC2/3 NG, and MPC7E).
• The SCBE3-MX Enhanced Switch Control Board provides improved fabric performance
and bandwidth capabilities for high-capacity line cards using the ZF-based switch
fabric.
Table 4 on page 31 compares the SCB capacities of MX series universal routers.
Table 75 on page 136 lists the supported routing engines per SCB.
Table 74: Switch Control Board Capacities for MX Series Universal Routers (Full-Duplex)
MX960 Fabric
Bandwidth MX480 Fabric
Bandwidth MX240 Fabric
Bandwidth
Fabric Bandwidth Per Slot Description
Up to 33 Tbps Up to 18 Tbps Up to 6 Tbps Up to 1.5 Tbps (non-redundant
fabric configuration with MPC10E
line cards); 1 Tbps (redundant
fabric configuration with MPC10E
line cards) Enhanced MX Switch
Control Board
(SCBE3-MX)
Up to 10.56 Tbps Up to 5.76 Tbps Up to 1.92 Tbps Up to 480 Gbps (non-redundant
fabric configuration); 340 Gbps
(redundant fabric configuration) Enhanced MX Switch
Control Board
(SCBE2-MX)
Up to 5.25 Tbps Up to 2.79 Tbps Up to 930 Gbps Up to 240 Gbps (non-redundant
fabric configuration); 160 Gbps
(redundant fabric configuration) Enhanced MX Switch
Control Board
(SCBE-MX)
135 Copyright © 2019, Juniper Networks, Inc.
Chapter 1: Overview