Cisco Systems RJ-45-to-AUX manual Series Gigabit Switch Routers, 372

The MGX 8800 RPM also supports MPLS. It can act as a label edge router or label switch router. It also supports MPLS−VPNs via mulitprotocol BGP extentions, VPN route−target extended BGP community attributes, MPLS forwarding across backbone, and multiple routing/forwarding instances on the provider edge router.

As mentioned earlier, the Route Processor Module has an ATM deluxe port adaptor interface to the chassis backplane.

Advanced traffic management features are as follows:

∙ATM service classes: nrt−VBR, ABR, and UBR

∙Traffic shaping (per VC)

∙High−performance architecture

∙Extended VC capabilities

∙Up to 4,096 VCs

∙Up to 200 concurrent segmentation and reassemblies (SARs)

∙ATM adaptation layer 5 (AAL5) for data traffic

Advanced traffic management mechanisms in the ATM port adaptor (PA) architecture allow for the support of bursty, client/server traffic, while supporting applications that require guaranteed or best−effort service. The ATM PA traffic management capabilities—based on ATM Forum specifications—surpass those of any existing ATM interface in high−end routers.

12000 Series Gigabit Switch Routers

The 12000 series Gigabit Switch Router (GSR) is designed and developed for the core of service provider and enterprise IP backbones. The Cisco 12000 GSR family includes three models:

∙12008—An eight−slot chassis switch that can be used to support up to 84 DS3, 28 OC−3c/STM−1c, and 28 OC−12c/STM−4c or 7 OC−48c/STM−16c interfaces

∙12012—Has 12 slots that can be used to support up to 132 DS3, 44 OC−3c/STM−1c, 44 OC−12c/STM−4c, or 11 OC−48c/STM−16c interfaces

∙12016—The new 5Tbps GSR terabit system, which has 16 slots that can be used to support up to 180 DS3, 60 OC−3c/STM−1c, and 60 OC−12c/STM−4c or 15 OC−48c/STM16c interfaces, with support for 15 OC−192c/STM−64c interfaces in the future

You may wonder why a router is being featured in a book about switches. The 12000 series belongs in this book because of its integrated switching fabric. At the heart of the Cisco 12000 GSR is a multigigabit crossbar switch fabric that is optimized to provide high−capacity switching at gigabit rates.

The crossbar switch enables high performance for two reasons: Connections from the LCs to a centralized fabric are point−to−point links that can operate at very high speeds; and, multiple bus transactions can be supported simultaneously, increasing the aggregate bandwidth of the system. A GSR system can be configured as 40Gbps for the 12008, 60Gbps for the 12012, and 80Gbps for the 12016, scalable to 5 terabits.

The switch fabric includes two card types: switch−fabric cards (SFCs) and clock and scheduler cards (CSC). Each GSR must have at least one CSC in the chassis. The SFCs receive the scheduling information and clocking reference from the CSC cards and perform the switching functions.

The Gigabit Route Processor (GRP) is a high−performance engine that provides the routing intelligence for the 12000 GSR family. It is dedicated to determining the network topology and calculating the best path across the network. The GRP has the following hardware characteristics:

∙200MHz R5000 CPU

∙Optionally, up to 256MB CPU DRAM (default 128MB)

∙512K Layer 2 cache

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