M160 Internet Router Hardware Guide

Some PICs, such as selected Gigabit Ethernet PICs, accept small form factor pluggables (SFPs), which are fiber-optic transceivers that can be removed from the PIC. Various SFPs have different reach characteristics. You can mix them in a single PIC and change the combination dynamically. SFPs are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs) on page 4. For SFP replacement instructions, see “Replace an SFP” on page 190. For information about PICs that use SFPs, see the M160 Internet Router PIC Guide.

You can install up to four PICs in an FPC. The number of ports on a PIC depends on the type of PIC. PICs are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs) on page 4. For PIC replacement instructions, see “Replacing a PIC” on page 179.

PIC Components

Most PICs supported on the M160 router have the following components. For complete specifications, see the M160 Internet Router PIC Guide. For information about pinouts for PIC cable connectors, see “Cable Connector Pinouts” on page 269.

One or more cable connector ports—Accept a network media connector.

LEDs—Indicate PIC and port status. Most PICs have an LED labeled STATUS on the PIC faceplate. Some PICs have additional LEDs, often one per port. The meaning of the LED states differs for various PICs. For more information, see the M160 Internet Router PIC Guide.

Offline button—Prepares the PIC for removal from the FPC when pressed. For the PICs that install on an FPC1, the offline button for each PIC is next to it on the FPC card carrier. For the PICs that install on an FPC2, the offline button is on the PIC faceplate. See Figure 6.

Flexible PIC Concentrators (FPCs)

Flexible PIC Concentrators (FPCs) house the PICs that connect the router to network media (for information about PICs, see “Physical Interface Cards (PICs)” on page 13). The main function of an FPC is to connect the PICs installed in it to the other router components. An I/O Manager ASIC on the FPC divides each incoming data packet into 64-byte cells and passes the cells through the midplane to the SFM, where another ASIC decides how to distribute them among the memory buffers located on and shared by all installed FPCs. After the SFM decides how to forward a packet, an I/O Manager ASIC on the FPC reassembles the corresponding data cells back into network-packet form and passes the packet to the appropriate PIC for transmission to the network. For more information, see “Data Flow through the Packet Forwarding Engine” on page 52.

Up to eight FPCs install vertically into the midplane from the front of the chassis. The FPC slots are numbered from FPC0 to FPC7, left to right. Each FPC accommodates up to four PICs. The PIC slots in each FPC are numbered from 0 (zero) through 3, top to bottom. An FPC can be installed into any FPC slot, regardless of the PICs it contains, and any combination of slots can be used. If a

14 Packet Forwarding Engine

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Juniper Networks M160 manual PIC Components, Flexible PIC Concentrators FPCs