3troubleshootingjunos

Reproductionhot-insertable and hot-removable. The Craft Interface is the

front of

M120 Multis rvice Edge Router Major Components

The major compon nts of the M120 from the front view are the following:

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ESD point: Consists of two electrostatic discharge (ESD) points (banana

for

plug receptacles)—one front and one rear.

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Craft Interface: Allows you to view status and troubleshooting information

at a glance and to perform many system control functions. It is

the router above the upper fan tray

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FPCs: The FPC slots on the router are two-PICs wide and two PICs tall,

allowing four Type 1 or Type 2 PICs and one Type 3 PIC to share power

circuits and a CPU and still fit in a quarter rack. Up to four FPCs install

vertically in the front of the router. Additionally, the M120 has slots for

two compact FPCs (cFPCs). These cFPCs contain an entire PFE and Type

3 PIC in a PIC-sized form factor.

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Fan tray: All chassis fans are redundant. In a failure situation, the Control

Board is responsible for increasing the speed of the remaining fans to

provide the necessary cooling.

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Routing Engines: The RE is an Intel-based Peripheral Component

Interconnect (PCI) platform that runs JUNOS Software. Software

processes that run on the RE maintain the routing tables, manage the

routing protocols used on the router, control the router interfaces, control

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some chassis components, and provide the interface for system

management and user access to the router. You can install one or two

REs in the router. The REs install into the rear of the chassis, directly i to

the Control Board, in vertical slots labeled CB0 and CB1.

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Control Boards (CBs): Each CB works with an installed RE

pr v de

control and monitoring functions for the router. These func

ns nclude

determining RE mastership, controlling power and reset for

he o her

router components, connecting the FEBs, monitoring and on rolling fan

speed, and monitoring system status. You can install one or two CBs in

the router.

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Forwarding Engine Boards (FEBs): The FEBs provide ro te lookup and

forwarding functions from the PICs an cFPCs. The midplane architecture

allows any FEB to carry traffic for any FPC. Depending on the bandwidth

and streams of the FEB, it can carry the traffic of multiple FPCs. To

provide redundancy, the FPC-FEB c nnections combine with 20 Gbps of

bandwidth between each pair f cards. System software configuration

determines which FPCs a given FEB supp rts and configures switches on

the FEB or FPC acco dingly. In addition, in the event of a FEB failure, a

standby FEB can quickly take over packet forwarding.

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Power Entry Modul s (PEMs): The M120 is configurable with either two

AC pow r suppli s or two DC power supplies. If one power supply fails or

you remove it, the maining power supply instantly assumes the entire

electrical load. Each AC power supply has two AC appliance inlets that

require a dedicated AC power feed. For 100-120 VAC, both inlets are in

for

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M320 Hardware Com onents

The hardware compon nts for the M320 include the following:

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Four AC or DC power supplies: The maximum chassis power is

3150 watts (65 A at -48 VDC) when fully loaded. Each AC supply provides

for

power to all components. In the DC power configuration, the DC power

supplies in slots PEM0 and PEM2 are load-sharing and provide power to

the FPCs in slots FPC3 through FPC7. The DC power supplies in slots

PEM1 and PEM3 are load-sharing and provide power to the FPCs in slots

FPC0 through FPC2, Switch Interface Boards (SIBs), CBs, and REs. All DC

power supplies provide power to the fan trays. The DC power supplies are

fully redundant. The DC power supplies in slots PEM0 and PEM1 can

provide full power to the router. Likewise, the DC power supplies in slots

PEM2 and PEM3 can also provide full power. The DC power supply in

PEM2 serves as the backup to the DC power supply in slot PEM0, and the

DC power supply in PEM3 serves as the backup to the DC power supply in

slot PEM1.

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Sheet metal chassis.

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Redundant cooling.

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