Physical Interface Cards (PICs) physically connect the router to network media. They are housed in Flexible PIC Concentrators (FPCs); for more information about FPCs, see Flexible PIC Concentrators (FPCs). (Quad-wide PICs, such as the 4-port Gigabit Ethernet and OC48/STM16 SONET/SDH PICs, are an exception. Such PICs occupy an entire FPC slot in the chassis and insert directly into the slot rather than into an FPC card carrier.)
PICs receive incoming packets from the network and transmit outgoing packets to the network, performing framing and line-speed signaling for their media type as required. PICs also encapsulate outgoing packets received from the FPCs before transmitting them. The controller ASIC on each PIC performs additional control functions specific to the PIC media type.
The router supports various PICs, including ATM, Channelized, Gigabit Ethernet, IP Services, and SONET/SDH interfaces. For complete PIC specifications, see the M20 PIC 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). For SFP replacement instructions, see Replacing an SFP. For information about PICs that use SFPs, see the M20 PIC Guide.
A regular PIC installs into one of the four slots in an FPC card carrier. The PIC slots are numbered from 0 (zero) through 3, right to left. The number of ports on a PIC depends on the type of PIC.
A regular PIC is hot-removable and hot-insertable in the sense that its absence does not disrupt routing functions; however, you must completely remove its host FPC from the chassis before removing the PIC, which affects all PICs on the FPC.
Quad-wide PICs, such as the 4-port Gigabit Ethernet and OC48/STM16 SONET/SDH PICs, occupy an entire FPC slot and are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs). The instructions for replacing a quad-wide PIC are the same as for an FPC. See Replacing an FPC.
For replacement instructions for regular PICs, see Replacing a PIC.
Most PICs supported on the M20 router have the following components. For complete specifications, see the M20 PIC Guide. For information about pinouts for PIC cable connectors, see Cable Connector Pinouts.