Cisco Systems Cisco 12816 Manuale Utente

Two types of RPs are available: a Gigabit Route Processor (GRP) or a 
Performance Route Processor (PRP). The GRP is the route processor that shipped 
with earlier Cisco 12000 series routers; the PRP is the route processor shipping 
with all current Cisco 12000 series routers. You cannot mix GRPs with PRPs. If 
you install a redundant RP, it must be the same type as the primary RP.

This publication uses the term route processor (RP) to indicate either a Gigabit 
Route Processor (GRP) or a Performance Route Processor (PRP) unless otherwise 
specified. 

Each system includes at least one RP that performs a variety of functions 
including the following:

Downloads the Cisco IOS software to all installed line cards at power-on.

Processes the network routing protocols and distributes updates to Cisco 
Express Forwarding (CEF) tables on the line cards.

Communicates with the line cards, either through the switch fabric or the 
maintenance bus (MBus):

The switch fabric connection is the main data path for distributing 
routing tables, as well as packets passed between the RP and the line 
cards.

The MBus connection allows the RP to download a system bootstrap 
image, collect or load diagnostic information, and perform general, 
internal system maintenance operations.

The GRP uses an IDT R5000 Reduced Instruction Set Computing (RISC) CPU 
that runs at an external bus clock speed of 100 MHz and has an internal clock 
speed of 200 MHz. 

 identifies the connectors and LEDs on the GRP front panel.