Specifications

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Media-specific ASICs
The media-specific ASICs perform physical layer functions, such as framing.
Each PIC is equipped with an ASIC or FPGA that performs control functions
tailored to the PIC's media type. SDH/SONET Manager ASIC
§ ATM Manager ASIC
§ DS-3 Manager FPGA
§ Gigabit Ethernet Manager ASIC
Packet Forwarding Engine
The PFE provides Layer 2 and Layer 3 packet switching, route lookups, and
packet forwarding. It forwards an aggregate of up to 160 Mpps for all packet sizes
under all network conditions. The aggregate throughput is over 160 Gbps simplex
or 80 Gbps full duplex with eight 12.8-Gbps FPCs installed.
The PFE supports the same ASIC-based features supported by the M20 and M40
routers. For example, class-of-service features include policing, classification,
priority queuing, Random Early Detection and Weighted Round Robin to increase
bandwidth efficiency. Filtering and sampling are also available for restricting
access, increasing security, and analyzing network traffic using the Internet
Processor II ASIC.
Finally, the PFE delivers maximum stability during exceptional conditions, while
also providing a significantly lower part count. This stability reduces power
consumption and increases mean time between failure.
Flexible PIC Concentrators
The FPCs house PICs and connect them to the rest of the router so that incoming
packets are then forwarded across the midplane to the appropriate destination
port. Each FPC slot contains an FPC1, FPC2, or an OC-192c/STM-64 PIC. There
are four dedicated 3.2-Gbps full-duplex channels (one per SFM) between each
M160 FPC slot and the core of the PFE.
Each FPC contains shared memory for storing data packets received; the
Distributed Buffer Manager ASICs on each SFM manage this memory. Each FPC
also contains two Packet Director ASICs for sending bytes to each of the four I/O
Manager ASICs, also located on the FPC.
Physical Interface Cards
PICs provide a complete range of fiber optic and electrical transmission interfaces
to the network. All PICs except the OC-192c/STM-64 occupy one of four PIC
spaces in an FPC (that is, they are single-wide). The OC-192c/STM-64 PIC
occupies an entire FPC slot.
The M160 router offers flexibility and conserves valuable rack space by
supporting the PICs and port densities described in the following table.
Additionally, it supports the Tunnel Services PIC, which enables the M160 router
to function as the ingress or egress point of an IP-IP unicast tunnel, a Cisco
generic routing encapsulation (GRE) tunnel, or a Protocol Independent Multicast -
Sparse Mode (PIM-SM) tunnel. The Tunnel Services PIC delivers OC-48/STM-16
bandwidth, but does not have a physical interface due to its loopback function
within the M160 chassis.
OC-192c/STM-64 PIC
The Juniper Networks OC-192c/STM-64 is the first 10-Gbps OC-192c/STM-64
interface on the market. Using the new SONET Manager II ASIC, this PIC yields
a full 10-Gbps throughput at wire rate for any packet size, under all network
conditions.
§ The OC-192c/STM-64 PIC combines the functions of a PIC and an FPC.
§ Like other PICs, it also provides the physical interface to the network.
§ Like the FPCs, it contains shared memory, two Packet Director ASICs,
and four I/O Manager ASICs. Additionally, the OC-192c/STM-64 PIC
resides in an FPC slot.
Switching and Forwarding Modules
The SFMs perform route lookup, filtering, and sampling, as well as provide
switching to the destination FPC. Hosting both the Internet Processor II ASIC and
two Distributed Buffer Manager ASICs, the SFM is responsible for making
forwarding decisions, distributing packets throughout memory, and forwarding