Cisco Systems 12000

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•State of the art queuing and congestion management techniques: Random Early Detection (RED), Weighted RED

(WRED) and Deﬁcit Round Robin (DRR) that provides an enhanced Weighted Fair Queuing mechanism

•MPLS Switching support to deliver the scalable trafﬁc engineering features

•Carrier Class Design

•Redundancy in all key system components, i.e. processors, switch fabric, line cards, power and cooling, to minimize

network disruption in the event of a failure

•Hot-swap capability enables components to be added or removed without service disruption

•Switch fabric redundancy provides fail-over to backup fabric with no data or user session loss

•APS/MPS enables SONET/SDH resiliency capabilities for providing interface redundancy

•NetworkEquipment Building System (NEBS) and European Telecommunications Standards Institute (ETSI) compliance

for installation in service provider central-ofﬁces.

Key Features and Beneﬁts

Cisco 12000 Series Architecture

System Level

The Cisco 12000 Series is based on a high speed distributed routing architecture combined with state-of-the-art switching

core that delivers Layer 3 routing at gigabit speeds.

TheCisco 12000 Series is optimized for performing routing and packet forwarding functions to transport IP datagrams across

a network. The routing function is performed in the Gigabit Route Processors (GRP) responsible for running the routing

protocols and building the routing tables from the network topology. This information is then used to build the forwarding

tables distributed to the line cards. In addition, the GRP is also responsible for the system control and administrative

functions.

•Thepacket forwarding functions are performed by each of the line card (LC). A copy of the forwarding tables computed

by the GRP is distributed to each of the line cards in the system. Each line card performs independent lookup of a

destinationaddress for each datagram received on a local copy of the forwarding table and the datagram is switched across

a crossbar switch fabric to the destination line card.

Allcards are installed from the front of the chassis and plug into a passive backplane. This backplane contains serial lines

that interconnect all of the line cards to the switch fabric cards as well as other connections for power and maintenance

functions.Each slot in the Cisco 12000 Series has up to 4 serial line connections (1.25 Gbps), one to each of the switch

fabriccards (see below) to provide a total capacity of 5 Gbps per slot (2.5 Gbps full duplex). The 12410/12416 utilizes 4

sets of 4 serial line connections in each slot, providing each slot with a switching capacity of 10 Gbps full duplex.

•Switch Fabric

Atthe heart of the Cisco 12000 Series is a multi-gigabit crossbar switch fabric that is optimized to provide high capacity

switchingat gigabit rates. The crossbar switch enables high performance for two reasons: connections from the line cards

to a centralized fabric are point-to-point links that can operate at very high speeds; multiple bus transactions can be

supportedsimultaneously increasing the aggregate bandwidth of the system. A Cisco 12000 Series switching fabric must

beconﬁgured to full fabric (40 Gbps for 12008, 60 Gbps for 12012, 80 Gbps for 12016, 200Gbps for 12410, and 320Gbps

for12416) in order to support all the current line cards. Please note that the number of fabric cards needed to be installed

for a full fabric set will differ according to each chassis.

Theswitch fabric includes two card types: Switch Fabric Cards (SFC) and Clock and Scheduler Cards (CSC). Each Cisco

12000Series must have at least one CSC in the chassis. The CSC handles requests from line cards, issues grants to access

the fabric and provides a reference clock to all the cards in the system to synchronize data transfer across the crossbar.

The SFC receives the scheduling information and clocking reference from the CSC cards and performs the switching

functions.