M160 Internet Router Hardware Guide
Some PICs, such as selected Gigabit Ethernet PICs,accept small form factor
pluggables (SFPs), which are fiber-optic transceivers th at can be removedfrom
the PIC. Various SFPs have different reach characteristics. You can mix them in
a single PIC and change the combinationdynamically. SFPs are hot-removable
and hot-insertable, as described in Field-Replaceab le 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 tofour PICs in an FPC. The number of ports on a PIC
depends on the type of PIC. PICs are hot-removableand hot-insertable, as
described in Field-ReplaceableUnits (FRUs) on page 4. For PIC replacement
instructions, see “Replacing a PIC” on page 179.
PIC Components
Most PICs supported on the M160 router havethe 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 connectorports—Accept a network media connector.
LEDs—Indicate PIC and port status. Most PICs havean 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 P ICs. For more information, see
the M160 Internet Router PIC Guide.
Offline button—Preparesthe PIC for removal from the FPC when pressed. For
the PICs that install on an FPC1, the offl ine 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
onthePICfaceplate. SeeFigure6.
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 installedin 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 ASICdecides how to distribute them among the memory buffers
located on and shared byall installed FPCs. After the SFM decides how to forward a
packet, an I/O Manager ASIC on the FPC reassembles the correspondingdata cells
back into network-packet form and passes the packet to the ap propriate 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 nu mbered from FPC0 to FPC7,lefttoright.EachFPC
accommodates up to four PICs. The PIC slots in each FPC are numbered from
0(zero) through 3, topto bottom. An FPC can be installed into any FPC slot,
regardless of thePICs it contains, and any combination of slots can be used. If a
14 Packet Forwarding Engine