Cfeb Components - Juniper M10i Hardware Manual

M10i Internet Router Hardware Guide
For CFEB replacement instructions, see
The CFEB communicates with the Routing Engine using a dedicated 100-Mbps Fast
Ethernet link that transfers routing table data from the Routing Engine to the
forwarding table in the integrated ASIC. The link is also used to transfer from the
CFEB to the Routing Engine routing link-state updates and other packets destined
for the router that have been received through the router interfaces.
The ASICs and other components on the CFEB provide the following functions:

CFEB Components

The CFEB has the following major components:
12
Compact Forwarding Engine Board (CFEB)
Route lookups—Performs route lookups using the forwarding table stored in the
synchronous SRAM (SSRAM).
Management of shared memory —Uniformly allocates incoming data packets
throughout the router's shared memory.
Transfer of outgoing data packets—Passes data packets to the destination FIC
or PIC when the data is ready to be transmitted.
Transfer of exception and control packets—Passes exception packets to the
microprocessor on the CFEB, which processes almost all of them. The remainder
are sent to the Routing Engine for further processing. Any errors originating in
the Packet Forwarding Engine and detected by the CFEB are sent to the Routing
Engine using system log messages.
Processing components:
266-MHz CPU and supporting circuitry
Integrated ASIC
33-MHz PCI bus
Storage components:
SDRAM for packet memory
SDRAM for the microkernel
SSRAM for route lookup
SSRAM for control memory
System interfaces:
100-Mbps Ethernet link for internal interface to the Routing Engine
19.44-MHz reference clock that generates clock signal for SONET/SDH PICs
I 2 C controller to read the I 2 C/EEPROMs in the PICs and temperature sensors
"Replacing a CFEB" on page 90.